Method and Apparatus for Detecting Man-In-The-Middle Attack

ABSTRACT

A system and method for detecting a man-in-the-middle attack, where the includes sending, by a secondary base station, a first check request message to a master base station, wherein the first check request message comprises first identifier information of an evolved random access bearer (ERAB) and a first data packet count value corresponding to the first identifier information; receiving, by the master base station, the first check request message; obtaining second identifier information that matches the first identifier information, wherein the second identifier information is an identifier of a data radio bearer (DRB) corresponding to the ERAB; sending a second check request message to a user terminal, wherein the second check request message comprises the first data packet count value and the second identifier information; and receiving, by the master base station, a check response message from the user terminal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/270,722, filed on Sep. 20, 2016, which claims priority toInternational Patent Application No. PCT/CN2015/072300, filed on Feb. 5,2015, which claims priority to Chinese Patent Application No.201410106876.4, filed on Mar. 21, 2014. All of the aforementioned patentapplications are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to the communications field, and inparticular, to a method and an apparatus for detecting aman-in-the-middle attack.

BACKGROUND

As informatization rapidly develops and network resources areincreasingly rich, a service capability of a master Evolved NodeB(Master eNB, or MeNB for short) cannot meet a user requirement due tolimited air interface bandwidth. In addition, expensive base stationconstruction costs and high radio frequency also increase difficulty inbase-station indoor coverage. Therefore, to improve a throughput of userplane data, a low-cost secondary eNodeB (Secondary eNB, or SeNB forshort) is combined with the MeNB in networking, and the SeNB offloadspartial traffic of the MeNB, which can resolve the foregoing problem.The master eNodeB is also referred to as a macro eNodeB (MacroeNB/cell), and the secondary eNodeB is also referred to as a small cell,which includes a pico cell/eNB and a femto cell/eNB. The small cell maybe referred to as a pico base station or a femto base station.

A user terminal such as a User Equipment (UE) simultaneously maintainsdual connectivity with the MeNB and the SeNB. The UE and the MeNBperform air-interface control plane signaling interworking with eachother, and the UE simultaneously transmits user plane data to the MeNBand the SeNB. Because the user plane data between the UE and the SeNB isprotected only by means of encryption processing, a man-in-the-middle(MITM) attack (MITM attack) may exist between the UE and the SeNB, andconsequently there is a risk that the user plane data of interworkingbetween the UE and the SeNB is inserted, tampered with, or forwarded,causing a user service to be fraudulently used and lawful interceptionto be unreliable, and the like.

In an existing communications network, after identifying a count value(e.g., a Packet Data Convergence Protocol (PDCP) count) of sent andreceived packets of a bearer between the UE and the eNB, the UE reportsthe count value to the eNB, such that the eNB detects whether aman-in-the-middle attack exists. A process is as follows. The eNB sendsa counter check message to the UE, and adds multiple first PDCP countvalues corresponding to all bearers between the UE and the eNB to acounter check request message. The UE separately determines bycomparison whether each first PDCP count value is the same as a storedsecond PDCP count value of each bearer. If the first PDCP count value ofeach of the bearers is the same as the second PDCP count value, the UEsends a check response message to the eNB. The check response messagedoes not carry any PDCP count value. Alternatively, if the first PDCPcount values of all the bearers are different from the second PDCP countvalue, the UE sends a check response message to the eNB, in which casethe check response message carries different second PDCP count values.The eNB performs check processing on the check response message. If thecheck response message does not carry any PDCP count value, thedetection procedure ends, and the eNB determines that noman-in-the-middle attack exists between the eNB and the UE.Alternatively, if the check response message carries the differentsecond PDCP count values, the eNB determines that a man-in-the-middleattack exists between the eNB and the UE, such that the eNB sends anotification message to a mobility management entity (MME) or anoperation and maintenance (O&M) server, and the MME or the O&M serverperforms subsequent processing and may release the bearer between the UEand the eNB.

It can be learned from the foregoing description that whether aman-in-the-middle attack exists between the UE and the eNB is detectedby means of air-interface control plane signaling interworking, but in ascenario in which the UE maintains dual connectivity with the MeNB andthe SeNB, no air-interface control plane signaling interworking occursbetween the SeNB and the UE. Consequently, in this scenario, the SeNBcannot detect whether a man-in-the-middle attack exists between the SeNBand the UE.

SUMMARY

Embodiments of the present disclosure provide a method and an apparatusfor detecting a man-in-the-middle attack, such that in a scenario inwhich UE maintains dual connectivity with an MeNB and an SeNB, it can bedetected whether the SeNB and the UE are attacked by aman-in-the-middle.

In a first aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includesreceiving, by a macro eNodeB (MeNB), a first check request message sentby a secondary eNodeB (SeNB), where the first check request messageincludes first identifier information of an evolved random access bearer(ERAB) and a first data packet count value corresponding to the firstidentifier information; generating, by the MeNB, a second check requestmessage according to the first identifier information; and sending thesecond check request message to a user terminal, where the second checkrequest message includes first indication information, the firstindication information is used to instruct the user terminal to obtainsecond identifier information that matches the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information, where the second identifier informationis a data radio bearer (DRB) corresponding to the ERAB. The methodfurther includes receiving, by the MeNB, a first check response messagegenerated by the user terminal according to the second check requestmessage, where the first check response message includes the secondidentifier information and the second data packet count value; anddetermining, by the MeNB when the first data packet count valuecorresponding to the first identifier information is the same as thesecond data packet count value corresponding to the second identifierinformation, that no man-in-the-middle attack exists between the SeNBand the user terminal; or determining, by the MeNB when the first datapacket count value corresponding to the first identifier information isdifferent from the second data packet count value corresponding to thesecond identifier information, that a man-in-the-middle attack existsbetween the SeNB and the user terminal.

With reference to the first aspect, in a first possible implementationmanner, the first check request message further includes an identifierof the SeNB. Additionally, generating, by the MeNB, a second checkrequest message according to the first identifier information, andsending the second check request message to a user terminal, where thesecond check request message includes first indication information, andthe first indication information is used to enable the user terminal toobtain second identifier information that matches the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information includes generating, by the MeNB, thesecond check request message according to the first identifierinformation and the identifier of the SeNB, and sending the second checkrequest message to the user terminal, such that the user terminalobtains, according to the second check request message, the secondidentifier information that matches the first identifier information andthe identifier of the SeNB, and the second data packet count valuecorresponding to the second identifier information.

With reference to the first aspect or the first possible implementationmanner of the first aspect, in a second possible implementation manner,the first check request message includes at least two pieces of firstidentifier information and at least two corresponding first data packetcount values, and the first check response message includes at least twopieces of second identifier information and at least two correspondingsecond data packet count values. Additionally, determining, by the MeNBwhen the first data packet count value corresponding to the firstidentifier information is different from the second data packet countvalue corresponding to the second identifier information, that aman-in-the-middle attack exists between the SeNB and the user terminalincludes determining, by the MeNB when a first data packet count valuecorresponding to at least one piece of first identifier information isdifferent from the second data packet count value corresponding to thesecond identifier information that matches the first identifierinformation, that a man-in-the-middle attack exists between the SeNB andthe user terminal. Alternatively, determining, by the MeNB when thefirst data packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information, that noman-in-the-middle attack exists between the SeNB and the user terminalincludes determining, by the MeNB when the first data packet countvalues corresponding to all the first identifier information are thesame as the second data packet count value corresponding to the secondidentifier information that matches the first identifier information,that no man-in-the-middle attack exists between the SeNB and the userterminal.

With reference to the first aspect or the first or the second possibleimplementation manner of the first aspect, in a third possibleimplementation manner, after the MeNB determines that noman-in-the-middle attack exists between the SeNB and the user terminal,the method further includes sending, by the MeNB, a second checkresponse message to the SeNB, where the second check response messageincludes second indication information, and the second indicationinformation is used to indicate that no man-in-the-middle attack existsbetween the SeNB and the UE.

With reference to the first aspect or the first, the second, or thethird possible implementation manner of the first aspect, in a fourthpossible implementation manner, after the MeNB determines that aman-in-the-middle attack exists between the SeNB and the user terminal,the method further includes sending, by the MeNB, an exception report toa mobility management entity MME or an operation and maintenance O&Mserver.

With reference to the first aspect or the first, the second, the third,or the fourth possible implementation manner of the first aspect, in afifth possible implementation manner, after the MeNB determines that aman-in-the-middle attack exists between the SeNB and the user terminal,the method further includes sending, by the MeNB, a third check responsemessage to the SeNB, where the third check response message includesthird indication information, and the third indication information isused to indicate that a man-in-the-middle attack exists between the SeNBand the user terminal.

In a second aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includessending, by an SeNB, a first check request message to an MeNB, where thefirst check request message includes first identifier information of anERAB and a first data packet count value corresponding to the firstidentifier information, and the first check request message is used toenable the MeNB to generate a second check request message according tothe first identifier information, and send the second check requestmessage to a user terminal; and receiving, by the SeNB, the checkresponse message sent by the MeNB. Additionally, when the check responsemessage is a second check response message and the second check responsemessage includes second indication information, the method includesdetermining, by the SeNB according to the second indication information,that no man-in-the-middle attack exists between the SeNB and the userterminal. Alternatively, when the check response message is a thirdcheck response message and the third check response message includesthird indication information, the method determining, by the SeNBaccording to the third indication information, that a man-in-the-middleattack exists between the SeNB and the user terminal, and taking apreset measure for processing.

With reference to the second aspect, in a first possible implementationmanner of the second aspect, the first check request message furtherincludes an identifier of the SeNB. Additionally, sending, by an SeNB, afirst check request message to an MeNB, where the first check requestmessage includes first identifier information of an ERAB and a firstdata packet count value corresponding to the first identifierinformation, and the first check request message is used to enable theMeNB to generate a second check request message according to the firstidentifier information, and send the second check request message to auser terminal includes sending, by the SeNB, the first check requestmessage to the MeNB, where the first check request message includes theidentifier of the SeNB, the first identifier information of the ERAB,and the first data packet count value corresponding to the firstidentifier information, and the first check request message is used toenable the MeNB to generate the second check request message accordingto the first identifier information and the identifier of the SeNB, andsend the second check request message to the user terminal.

In a third aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includesreceiving, by a user terminal, a second check request message sent bythe MeNB, where the second check request message includes secondidentifier information corresponding to first identifier information ofan ERAB, and the second identifier information is a DRB corresponding tothe ERAB; obtaining, by the user terminal, the second identifierinformation corresponding to the first identifier information, and asecond data packet count value corresponding to the second identifierinformation; and sending, by the user terminal, the second identifierinformation and the second data packet count value corresponding to thesecond identifier information to the MeNB, such that the MeNBdetermines, according to a first data packet count value and the seconddata packet count value, whether a man-in-the-middle attack exists.

In a fourth aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includesreceiving, by an MeNB, a first check request message sent by an SeNB,where the first check request message includes first identifierinformation of an ERAB and a first data packet count value correspondingto the first identifier information; generating, by the MeNB, a secondcheck request message according to the first identifier information andthe first data packet count value corresponding to the first identifierinformation; and sending the second check request message to a userterminal, where the second check request message includes firstindication information, the first indication information is used toinstruct the user terminal to obtain second identifier information thatmatches the first identifier information, and a second data packet countvalue corresponding to the second identifier information, and determineby comparison whether the first data packet count value corresponding tothe first identifier information is the same as the second data packetcount value corresponding to the second identifier information, and thesecond identifier information is a DRB corresponding to the ERAB. Themethod further includes receiving, by the MeNB, a check response messagegenerated by the user terminal according to the second check requestmessage, and sending the check response message to the SeNB, such thatthe SeNB performs processing according to the response message.

With reference to the fourth aspect, in a first possible implementationmanner of the fourth aspect, the first check request message furtherincludes an identifier of the SeNB. Additionally, generating, by theMeNB, a second check request message according to the first identifierinformation and the first data packet count value corresponding to thefirst identifier information, and sending the second check requestmessage to a user terminal, where the second check request messageincludes first indication information, and the first indicationinformation is used to instruct the user terminal to obtain secondidentifier information that matches the first identifier information,and a second data packet count value corresponding to the secondidentifier information, and determine by comparison whether the firstdata packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information includes generating,by the MeNB, the second check request message according to theidentifier of the SeNB, the first identifier information, and the firstdata packet count value corresponding to the first identifierinformation, and sending the second check request message to the userterminal, where the second check request message includes the firstindication information, and the first indication information is used toinstruct the user terminal to obtain the second identifier informationthat matches the first identifier information and the identifier of theSeNB, and the second data packet count value corresponding to the secondidentifier information, and determine by comparison whether the firstdata packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information.

With reference to the fourth aspect or the first possible implementationmanner of the fourth aspect, in a second possible implementation mannerof the fourth aspect, after receiving, by the MeNB, a check responsemessage generated by the user terminal according to the second checkrequest message, and sending the check response message to the SeNB,such that the SeNB performs processing according to the responsemessage, the method further includes, when the MeNB receives anexception report sent by the SeNB, sending, by the MeNB, the exceptionreport to an MME or an O&M server.

In a fifth aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includessending, by an SeNB, a first check request message to an MeNB, where thefirst check request message includes first indication information, andthe first indication information is used to instruct the MeNB to send asecond check request message to a user terminal; receiving, by the SeNB,a check response message sent by the MeNB; and determining, by the SeNBaccording to the check response message, whether a man-in-the-middleattack exists. Additionally, when determining that the man-in-the-middleattack exists, the method includes taking, by the SeNB, a preset measurefor processing and sending an exception report to the MeNB.

In a sixth aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includesreceiving, by a user terminal, a second check request message sent by anMeNB, where the second check request message includes second identifierinformation corresponding to first identifier information of an ERAB,and a first data packet count value corresponding to the firstidentifier information, and the second identifier information is a DRBcorresponding to the ERAB; obtaining, by the user terminal, the secondidentifier information corresponding to the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information; determining, by the user terminalaccording to the first data packet count value corresponding to thefirst identifier information, and the second data packet count valuecorresponding to the second identifier information, whether aman-in-the-middle attack exists between an SeNB and the user terminal;and generating, by the user terminal, a check response message accordingto a result of the determining, and sending the check response messageto the MeNB.

With reference to the sixth aspect, in a first possible implementationmanner of the sixth aspect, determining, by the user terminal accordingto the first data packet count value corresponding to the firstidentifier information and the second data packet count valuecorresponding to the second identifier information, whether aman-in-the-middle attack exists between an SeNB and the user terminalincludes determining, by the user terminal when the first data packetcount value corresponding to the first identifier information is thesame as the second data packet count value corresponding to the secondidentifier information, that no man-in-the-middle attack exists betweenthe SeNB and the user terminal. Alternatively, determining, by the userterminal according to the first data packet count value and the seconddata packet count value, whether a man-in-the-middle attack existsbetween an SeNB and the user terminal includes determining, by the userterminal when the first data packet count value corresponding to thefirst identifier information is different from the second data packetcount value corresponding to the second identifier information, that aman-in-the-middle attack exists between the SeNB and the user terminal.

In a seventh aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includesreceiving, by an MeNB, a first check request message sent by an SeNB;generating, by the MeNB, a second check request message according to thefirst check request message; and sending the second check requestmessage to a user terminal, where the second check request messageincludes first indication information, and the first indicationinformation is used to instruct the user terminal to obtain firstidentifier information of a DRB and a first data packet count valuecorresponding to the first identifier information. The method furtherincludes receiving, by the MeNB, a check response message generated bythe user terminal according to the second check request message, andsending the check response message to the SeNB, where the responsemessage includes the first identifier information and the first datapacket count value corresponding to the first identifier information,such that the SeNB determines, according to the first data packet countvalue, whether a man-in-the-middle attack exists.

With reference to the seventh aspect, in a first possible implementationmanner of the seventh aspect, the first check request message furtherincludes an identifier of the SeNB. Additionally, generating, by theMeNB, a second check request message according to the first checkrequest message, and sending the second check request message to a userterminal, where the second check request message includes firstindication information, and the first indication information is used toinstruct the user terminal to obtain first identifier information of aDRB and a first data packet count value corresponding to the firstidentifier information includes generating, by the MeNB, the secondcheck request message according to the identifier of the SeNB and thefirst check request message, and sending the second check requestmessage to the user terminal, where the second check request messageincludes the first indication information, and the first indicationinformation is used to instruct the user terminal to obtain the firstidentifier information of the DRB and the first data packet count valuecorresponding to the first identifier information.

With reference to the seventh aspect or the first possibleimplementation manner of the seventh aspect, in a second possibleimplementation manner of the seventh aspect, after the receiving, by theMeNB, a check response message generated by the user terminal accordingto the second check request message, and sending the check responsemessage to the SeNB, the method further includes, when the MeNB receivesan exception report sent by the SeNB, sending, by the MeNB, theexception report to a mobility management entity MME or an operation andmaintenance O&M server.

In an eighth aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includessending, by an SeNB, a first check request message to an MeNB, where thefirst check request message is used to enable the MeNB to generate asecond check request message according to the first check requestmessage, and send the second check request message to a user terminal;receiving, by the SeNB, a check response message sent by the MeNB, wherethe check response message includes first identifier information of aDRB and a first data packet count value corresponding to the firstidentifier information; obtaining, by the SeNB according to the firstidentifier information, second identifier information that matches thefirst identifier information, and a second data packet count valuecorresponding to the second identifier information, where the secondidentifier information is an ERAB corresponding to the DRB; anddetermining, by the SeNB according to the first data packet count valueand the second data packet count value, whether a man-in-the-middleattack exists. Additionally, when determining that the man-in-the-middleattack exists, the method includes taking, by the SeNB, a preset measurefor processing and sending an exception report to the MeNB.

With reference to the eighth aspect, in a first possible implementationmanner of the eighth aspect, determining, by the SeNB according to thefirst data packet count value and the second data packet count value,whether a man-in-the-middle attack exists includes determining, by theSeNB when the first data packet count value corresponding to the firstidentifier information is the same as the second data packet count valuecorresponding to the second identifier information, that noman-in-the-middle attack exists between the SeNB and the user terminal;or determining, by the SeNB when the first data packet count valuecorresponding to the first identifier information is different from thesecond data packet count value corresponding to the second identifierinformation, that a man-in-the-middle attack exists between the SeNB andthe user terminal.

In a ninth aspect, an embodiment of the present disclosure provides amethod for detecting a man-in-the-middle attack. The method includesreceiving, by a user terminal, a second check request message sent by anMeNB; obtaining, by the user terminal according to the second checkrequest message, first identifier information of a DRB and a first datapacket count value corresponding to the first identifier information;and sending, by the user terminal, a check response message to the MeNB,where the check response message includes the first identifierinformation and the first data packet count value corresponding to thefirst identifier information, such that the MeNB sends the checkresponse message to an SeNB, and the SeNB determines, according to thefirst data packet count value, whether a man-in-the-middle attack existsbetween the SeNB and the user terminal.

In a tenth aspect, an embodiment of the present disclosure provides anapparatus for detecting a man-in-the-middle attack. The apparatusincludes a receiving unit configured to receive a first check requestmessage sent by an SeNB, where the first check request message includesfirst identifier information of an ERAB and a first data packet countvalue corresponding to the first identifier information; and a sendingunit configured to generate a second check request message according tothe first identifier information, and send the second check requestmessage to a user terminal, where the second check request messageincludes first indication information, the first indication informationis used to instruct the user terminal to obtain second identifierinformation that matches the first identifier information, and a seconddata packet count value corresponding to the second identifierinformation, and the second identifier information is a DRBcorresponding to the ERAB. The receiving unit is further configured toreceive a first check response message generated by the user terminalaccording to the second check request message, where the first checkresponse message includes the second identifier information and thesecond data packet count value. and the apparatus further includes ajudging unit configured such that when the first data packet count valuecorresponding to the first identifier information is the same as thesecond data packet count value corresponding to the second identifierinformation, the judging unit determines that no man-in-the-middleattack exists between the SeNB and the user terminal. Alternatively,when the first data packet count value corresponding to the firstidentifier information is different from the second data packet countvalue corresponding to the second identifier information, the judgingunit determines that a man-in-the-middle attack exists between the SeNBand the user terminal.

With reference to the tenth aspect, in a first implementation manner ofthe tenth aspect, the first check request message received by thereceiving unit further includes an identifier of the SeNB. Additionally,the sending unit is further configured to generate the second checkrequest message according to the first identifier information and theidentifier of the SeNB, and send the second check request message to theuser terminal, such that the user terminal obtains, according to thesecond check request message, the second identifier information thatmatches the first identifier information and the identifier of the SeNB,and the second data packet count value corresponding to the secondidentifier information.

With reference to the tenth aspect or the first possible implementationmanner of the tenth aspect, in a second possible implementation manner,the first check request message received by the receiving unit includesat least two pieces of first identifier information and at least twocorresponding first data packet count values, and the first checkresponse message received by the receiving unit includes at least twopieces of second identifier information and at least two correspondingsecond data packet count values. Additionally, the judging unit isconfigured such that when a first data packet count value correspondingto at least one piece of first identifier information is different fromthe second data packet count value corresponding to the secondidentifier information that matches the first identifier information,the judging unit determines that a man-in-the-middle attack existsbetween the SeNB and the user terminal. Alternatively, the judging unitis configured such that when the first data packet count valuescorresponding to all the first identifier information are the same asthe second data packet count value corresponding to the secondidentifier information that matches the first identifier information,the judging unit determines that no man-in-the-middle attack existsbetween the SeNB and the user terminal.

With reference to the tenth aspect or the first or the second possibleimplementation manner of the tenth aspect, in a third possibleimplementation manner, the sending unit is further configured to send asecond check response message to the SeNB, where the second checkresponse message includes second indication information, and the secondindication information is used to indicate that no man-in-the-middleattack exists between the SeNB and the UE.

With reference to the tenth aspect or the first or the second or thethird possible implementation manner of the tenth aspect, in a fourthpossible implementation manner, the sending unit is further configuredto send an exception report to an MME or an O&M server.

With reference to the tenth aspect or the first or the second or thethird or the fourth possible implementation manner of the tenth aspect,in a fifth possible implementation manner of the tenth aspect, thesending unit is further configured to send a third check responsemessage to the SeNB, where the third check response message includesthird indication information, and the third indication information isused to indicate that a man-in-the-middle attack exists between the SeNBand the user terminal.

In an eleventh aspect, an embodiment of the present disclosure providesan apparatus for detecting a man-in-the-middle attack. The apparatusincludes a sending unit configured to send a first check request messageto an MeNB, where the first check request message includes firstidentifier information of an ERAB and a first data packet count valuecorresponding to the first identifier information, and the first checkrequest message is used to enable the MeNB to generate a second checkrequest message according to the first identifier information, and sendthe second check request message to a user terminal. The apparatusfurther includes a receiving unit configured to receive the checkresponse message sent by the MeNB, and a determining unit configuredsuch that when the check response message is a second check responsemessage and the second check response message includes second indicationinformation, the determining unit determines, according to the secondindication information, that no man-in-the-middle attack exists betweenthe SeNB and the user terminal. Alternatively, when the check responsemessage is a third check response message and the third check responsemessage includes third indication information, the determining unitdetermines, according to the third indication information, that aman-in-the-middle attack exists between the SeNB and the user terminal,and take a preset measure for processing.

With reference to the eleventh aspect, in a first possibleimplementation manner of the eleventh aspect, the first check requestmessage sent by the sending unit further includes an identifier of theSeNB. Additionally, the sending unit is configured to send the firstcheck request message to the MeNB, where the first check request messageincludes the identifier of the apparatus, the first identifierinformation of the ERAB, and the first data packet count valuecorresponding to the first identifier information, and the first checkrequest message is used to enable the MeNB to generate the second checkrequest message according to the first identifier information and theidentifier of the apparatus, and send the second check request messageto the user terminal.

In a twelfth aspect, an embodiment of the present disclosure provides anapparatus for detecting a man-in-the-middle attack. The apparatusincludes a receiving unit configured to receive a second check requestmessage sent by the MeNB, where the second check request messageincludes second identifier information corresponding to first identifierinformation of an ERAB, and the second identifier information is a DRBcorresponding to the ERAB; an obtaining unit configured to obtain thesecond identifier information corresponding to the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information; and a sending unit configured to send thesecond identifier information and the second data packet count valuecorresponding to the second identifier information to the MeNB, suchthat the MeNB determines, according to a first data packet count valueand the second data packet count value, whether a man-in-the-middleattack exists.

In a thirteenth aspect, an embodiment of the present disclosure providesan apparatus for detecting a man-in-the-middle attack. The apparatusincludes a receiving unit configured to receive a first check requestmessage sent by an SeNB, where the first check request message includesfirst identifier information of an ERAB and a first data packet countvalue corresponding to the first identifier information; and a sendingunit configured to generate a second check request message according tothe first identifier information and the first data packet count valuecorresponding to the first identifier information, and send the secondcheck request message to a user terminal, where the second check requestmessage includes first indication information, the first indicationinformation is used to instruct the user terminal to obtain secondidentifier information that matches the first identifier information,and a second data packet count value corresponding to the secondidentifier information. The sending unit is further configured todetermine by comparison whether the first data packet count valuecorresponding to the first identifier information is the same as thesecond data packet count value corresponding to the second identifierinformation, and the second identifier information is a DRBcorresponding to the ERAB. Additionally, the receiving unit is furtherconfigured to: receive a check response message generated by the userterminal according to the second check request message, and send thecheck response message to the SeNB, such that the SeNB performsprocessing according to the response message.

With reference to the thirteenth aspect, in a first possibleimplementation manner of the thirteenth aspect, the first check requestmessage received by the receiving unit further includes an identifier ofthe SeNB. Additionally, the sending unit is configured to generate thesecond check request message according to the identifier of the SeNB,the first identifier information, and the first data packet count valuecorresponding to the first identifier information, and send the secondcheck request message to the user terminal, where the second checkrequest message includes the first indication information, and the firstindication information is used to instruct the user terminal to obtainthe second identifier information that matches the first identifierinformation and the identifier of the SeNB, and the second data packetcount value corresponding to the second identifier information. Thesending unit is further configured to determine by comparison whetherthe first data packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information.

With reference to the thirteenth aspect or the first possibleimplementation manner of the thirteenth aspect, in a second possibleimplementation manner, the sending unit is further configured such thatwhen the receiving unit receives an exception report sent by the SeNB,the sending unit sends the exception report to an MME or an O&M server.

In a fourteenth aspect, an embodiment of the present disclosure providesan apparatus for detecting a man-in-the-middle attack. The apparatusincludes a sending unit configured to send a first check request messageto an MeNB, where the first check request message includes firstindication information, and the first indication information is used toinstruct the MeNB to send a second check request message to a userterminal, and a receiving unit configured to receive a check responsemessage sent by the MeNB. and the apparatus further includes adetermining unit configured to determine, according to the checkresponse message, whether a man-in-the-middle attack exists. The sendingunit is further configured such that when the determining unitdetermines that the man-in-the-middle attack exists, the sending unittakes a preset measure for processing and send an exception report tothe MeNB.

In a fifteenth aspect, an embodiment of the present disclosure providesan apparatus for detecting a man-in-the-middle attack. The apparatusincludes a receiving unit configured to receive a second check requestmessage sent by an MeNB, where the second check request message includessecond identifier information corresponding to first identifierinformation of an ERAB, and a first data packet count valuecorresponding to the first identifier information, and the secondidentifier information is a DRB corresponding to the ERAB. The apparatusfurther includes an obtaining unit configured to obtain the secondidentifier information corresponding to the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information; a judging unit configured to determine,according to the first data packet count value corresponding to thefirst identifier information, and the second data packet count valuecorresponding to the second identifier information, whether aman-in-the-middle attack exists between an SeNB and the apparatus; and asending unit configured to generate a check response message accordingto a result determined by the judging unit, and send the check responsemessage to the MeNB.

With reference to the fifteenth aspect, in a first possibleimplementation manner of the fifteenth aspect, when the first datapacket count value corresponding to the first identifier information isthe same as the second data packet count value corresponding to thesecond identifier information, the judging unit is configured todetermine that no man-in-the-middle attack exists between the SeNB andthe apparatus. Alternatively, when the first data packet count valuecorresponding to the first identifier information is different from thesecond data packet count value corresponding to the second identifierinformation, the judging unit is configured to determine that aman-in-the-middle attack exists between the SeNB and the apparatus.

In a sixteenth aspect, an embodiment of the present disclosure providesan apparatus for detecting a man-in-the-middle attack. The apparatusincludes a receiving unit configured to receive a first check requestmessage sent by an SeNB, and a sending unit configured to: generate asecond check request message according to the first check requestmessage, and send the second check request message to a user terminal,where the second check request message includes first indicationinformation, and the first indication information is used to instructthe user terminal to obtain first identifier information of a DRB and afirst data packet count value corresponding to the first identifierinformation. The receiving unit is further configured to receive a checkresponse message generated by the user terminal according to the secondcheck request message, and send the check response message to the SeNB,where the response message includes the first identifier information andthe first data packet count value corresponding to the first identifierinformation, such that the SeNB determines, according to the first datapacket count value, whether a man-in-the-middle attack exists.

With reference to the sixteenth aspect, in a first possibleimplementation manner of the sixteenth aspect, the first check requestmessage received by the receiving unit further includes an identifier ofthe SeNB. Additionally, the sending unit is configured to generate thesecond check request message according to the identifier of the SeNB andthe first check request message, and send the second check requestmessage to the user terminal, where the second check request messageincludes the first indication information, and the first indicationinformation is used to instruct the user terminal to obtain the firstidentifier information of the DRB and the first data packet count valuecorresponding to the first identifier information.

With reference to the sixteenth aspect or the first possibleimplementation manner of the sixteenth aspect, in a second possibleimplementation manner, the sending unit is further configured such thatwhen the receiving unit receives an exception report sent by the SeNB,the sending unit sends the exception report to an MME or an O&M server.

In a seventeenth aspect, an embodiment of the present disclosureprovides an apparatus for detecting a man-in-the-middle attack. Theapparatus includes a sending unit configured to send a first checkrequest message to an MeNB, where the first check request message isused to enable the MeNB to generate a second check request messageaccording to the first check request message, and send the second checkrequest message to a user terminal; a receiving unit configured toreceive a check response message sent by the MeNB, where the checkresponse message includes first identifier information of a DRB and afirst data packet count value corresponding to the first identifierinformation; an obtaining unit configured to obtain, according to thefirst identifier information, second identifier information that matchesthe first identifier information, and a second data packet count valuecorresponding to the second identifier information, where the secondidentifier information is an ERAB corresponding to the DRB; and ajudging unit configured to determine, according to the first data packetcount value and the second data packet count value, whether aman-in-the-middle attack exists. The sending unit is further configuredsuch that when the judging unit determines that the man-in-the-middleattack exists, the sending unit takes a preset measure for processingand send an exception report to the MeNB.

With reference to the seventeenth aspect, in a first possibleimplementation manner of the seventeenth aspect, the judging unit isconfigured such that when the first data packet count valuecorresponding to the first identifier information is the same as thesecond data packet count value corresponding to the second identifierinformation, the judging unit determines that no man-in-the-middleattack exists between the apparatus and the user terminal.Alternatively, when the first data packet count value corresponding tothe first identifier information is different from the second datapacket count value corresponding to the second identifier information,the judging unit determines that a man-in-the-middle attack existsbetween the apparatus and the user terminal.

In an eighteenth aspect, an embodiment of the present disclosureprovides an apparatus for detecting a man-in-the-middle attack. Theapparatus includes a receiving unit configured to receive a second checkrequest message sent by an MeNB, and an obtaining unit configured toobtain, according to the second check request message, first identifierinformation of a DRB and a first data packet count value correspondingto the first identifier information. and the apparatus further includesa sending unit configured to send a check response message to the MeNB,where the check response message includes the first identifierinformation and the first data packet count value corresponding to thefirst identifier information, such that the MeNB sends the checkresponse message to an SeNB, and the SeNB determines, according to thefirst data packet count value, whether a man-in-the-middle attack existsbetween the SeNB and the apparatus.

In conclusion, according to the method and the apparatus for detecting aman-in-the-middle attack provided in the embodiments of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack.An MeNB receives a first data packet count value that is of a bearerbetween the SeNB and UE and is sent by the SeNB, and requires, accordingto the first data packet count value sent by the SeNB, the UE to reporta second data packet count value of a bearer between the UE and theSeNB. When the first data packet count value is the same as the seconddata packet count value, the MeNB determines that no man-in-the-middleattack exists between the SeNB and the user terminal, and notifies theSeNB. Therefore, in a scenario in which the SeNB offloads traffic of theMeNB, the MeNB, the SeNB, and the UE all can participate in detection ofa man-in-the-middle attack.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 1 of the present disclosure;

FIG. 2 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 2 of the present disclosure;

FIG. 3 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 3 of the present disclosure;

FIG. 4 is a signaling diagram of detection of a man-in-the-middle attackaccording to an embodiment of the present disclosure;

FIG. 5 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 4 of the present disclosure;

FIG. 6 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 5 of the present disclosure;

FIG. 7 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 6 of the present disclosure;

FIG. 8 is a signaling diagram of detection of a man-in-the-middle attackaccording to an embodiment of the present disclosure;

FIG. 9 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 7 of the present disclosure;

FIG. 10 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 8 of the present disclosure;

FIG. 11 is a flowchart of a method for detecting a man-in-the-middleattack according to Embodiment 9 of the present disclosure;

FIG. 12 is a signaling diagram of detection of a man-in-the-middleattack according to an embodiment of the present disclosure;

FIG. 13 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 10 of the presentdisclosure;

FIG. 14 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 11 of the presentdisclosure;

FIG. 15 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 12 of the presentdisclosure;

FIG. 16 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 13 of the presentdisclosure;

FIG. 17 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 14 of the presentdisclosure;

FIG. 18 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 15 of the presentdisclosure;

FIG. 19 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 16 of the presentdisclosure;

FIG. 20 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 17 of the presentdisclosure;

FIG. 21 is a schematic structural diagram of an apparatus for detectinga man-in-the-middle attack according to Embodiment 18 of the presentdisclosure;

FIG. 22 is a schematic structural diagram of hardware of an apparatusfor detecting a man-in-the-middle attack according to Embodiment 19 ofthe present disclosure;

FIG. 23 is a schematic structural diagram of hardware of an apparatusfor detecting a man-in-the-middle attack according to Embodiment 20 ofthe present disclosure; and

FIG. 24 is a schematic structural diagram of hardware of an apparatusfor detecting a man-in-the-middle attack according to Embodiment 21 ofthe present disclosure.

DESCRIPTION OF EMBODIMENTS

To make the objectives, technical solutions, and advantages of theembodiments of the present disclosure clearer, the following clearly andcompletely describes the technical solutions in the embodiments of thepresent disclosure with reference to the accompanying drawings in theembodiments of the present disclosure. The described embodiments aresome but not all of the embodiments of the present disclosure. All otherembodiments obtained by a person of ordinary skill in the art based onthe embodiments of the present disclosure without creative efforts shallfall within the protection scope of the present disclosure.

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments of thepresent disclosure constitute no limitation to the present disclosure.

Embodiment 1

The following uses FIG. 1 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 1 of thepresent disclosure. FIG. 1 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 1 of the presentdisclosure, and this embodiment of the present disclosure is executed bya macro eNodeB (MeNB). As shown in FIG. 1, this embodiment includes thefollowing steps.

Step 110: The MeNB receives a first check request message sent by asecondary eNodeB (SeNB), where the first check request message includesfirst identifier information of an ERAB and a first data packet countvalue corresponding to the first identifier information.

The SeNB starts detection of a bearer between the SeNB and UE, and theSeNB sends the first check request message to the MeNB, where the firstcheck request message includes the first identifier information of theevolved random access bearer (ERAB) between the SeNB and the UE and thefirst data packet count value corresponding to the first identifierinformation.

The MeNB receives the first check request message.

The first data packet count value reflects a count, obtained by theSeNB, of sent and received data packets of the bearer between the SeNBand the UE.

It may be understood that there are multiple bearers between the SeNBand the UE, and each bearer has one piece of first identifierinformation. In this embodiment of the present disclosure, the firstcheck request message may include at least one piece of first identifierinformation corresponding to a bearer, and at least one first datapacket count value corresponding to the first identifier information.

Step 120: The MeNB generates a second check request message according tothe first identifier information, and sends the second check requestmessage to a user terminal, where the second check request messageincludes first indication information, the first indication informationis used to instruct the user terminal to obtain second identifierinformation that matches the first identifier information, and a seconddata packet count value corresponding to the second identifierinformation, and the second identifier information is a DRBcorresponding to the ERAB.

After receiving the first check request message, the MeNB determinesthat the SeNB starts detection of the bearer between the SeNB and theuser terminal UE, and the MeNB obtains the first identifier informationand the first data packet count value from the first check requestmessage.

The MeNB locally stores the first data packet count value, and generatesthe second check request message according to the first identifierinformation, where the second check request message includes the firstindication information, and the first indication information is used toinstruct the UE to obtain the second identifier information that matchesthe first identifier information and is of the DRB between the UE andthe SeNB, and the second data packet count value corresponding to thesecond identifier information.

The second data packet count value reflects a count, obtained by the UE,of sent and received data packets of the bearer between the SeNB and theUE.

It should be noted that because the first check request message mayinclude at least two pieces of first identifier information of a bearerand at least two corresponding first data packet count values in step110, when the UE obtains the second identifier information and thesecond data packet count value, the UE obtains, according to each pieceof first identifier information, second identifier informationcorresponding to each piece of first identifier information, and asecond data packet count value corresponding to the second identifierinformation.

Step 130: The MeNB receives a first check response message generated bythe user terminal according to the second check request message, wherethe first check response message includes the second identifierinformation and the second data packet count value.

The UE obtains, according to the second check request message, thesecond identifier information that matches the first identifierinformation, and the second data packet count value. The UE adds theobtained second identifier information and the obtained second datapacket count value to the first check response message, and sends thefirst check response message to the MeNB.

The MeNB receives the first check response message sent by the UE.

Step 140: When the first data packet count value corresponding to thefirst identifier information is the same as the second data packet countvalue corresponding to the second identifier information, the MeNBdetermines that no man-in-the-middle attack exists between the SeNB andthe user terminal.

In some implementations, the MeNB determines by comparison whether thefirst data packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information, and if the firstdata packet count value is the same as the second data packet countvalue, the MeNB determines that no man-in-the-middle attack existsbetween the SeNB and the UE.

According to the foregoing descriptions in step 110 and step 120,because there is at least one piece of first identifier information, atleast one piece of second identifier information, at least one firstdata packet count value, and at least one second data packet countvalue, and each piece of first identifier information is correspondingto each piece of second identifier information, that the MeNB determinesby comparison whether the first data packet count value is the same asthe second data packet count value is such that the MeNB determines bycomparison whether a first data packet count value corresponding to eachpiece of first identifier information is the same as a second datapacket count value corresponding to the second identifier informationthat matches each piece of first identifier information.

When first data packet count values corresponding to all firstidentifier information are the same as the second data packet countvalue corresponding to the second identifier information that matchesthe first identifier information, the MeNB determines that noman-in-the-middle attack exists between the SeNB and the UE.

After the MeNB determines that no man-in-the-middle attack existsbetween the SeNB and the UE, the MeNB sends a second check responsemessage to the SeNB, where the second check response message includessecond indication information, the second indication information is usedto indicate that no man-in-the-middle attack exists between the SeNB andthe UE, and the second indication information may be empty or mayinclude a character string, or the like, such as a character string “noman-in-the-middle attack exists”.

Step 150: When the first data packet count value corresponding to thefirst identifier information is different from the second data packetcount value corresponding to the second identifier information, the MeNBdetermines that a man-in-the-middle attack exists between the SeNB andthe user terminal.

In some implementations, the MeNB determines by comparison whether thefirst data packet count value is the same as the second data packetcount value, and if the first data packet count value is different fromthe second data packet count value, the MeNB determines that aman-in-the-middle attack exists between the SeNB and the UE.

Further, when a first data packet count value corresponding to at leastone piece of first identifier information is different from the seconddata packet count value corresponding to the second identifierinformation that matches the first identifier information, the MeNBdetermines that a man-in-the-middle attack exists between the SeNB andthe UE.

After the MeNB determines that a man-in-the-middle attack exists betweenthe SeNB and the UE, the MeNB sends a third check response message tothe SeNB, and the third check response message is used to indicate thata man-in-the-middle attack exists between the SeNB and the UE. Further,the third check response message may further include all second datapacket count values that are different from the first data packet countvalue corresponding to the first identifier information, and firstidentifier information corresponding to the second data packet countvalues, such that the SeNB determines that a man-in-the-middle attackexists between the SeNB and the user terminal. Alternatively, the thirdcheck response message may include only a result of the determining, forexample, a result that a man-in-the-middle attack exists or noman-in-the-middle attack exists.

After the MeNB sends the third check response message to the SeNB, theMeNB further sends an exception report to a mobility management entity(MME) or an operation and maintenance (O&M) server, such that the MME orthe O&M server takes a further measure. As an example instead of alimitation, the further measure is releasing or deleting the bearerbetween the SeNB and the user terminal, or counting, by the MME or theO&M server, received exception reports, and when a quantity of exceptionreports exceeds a quantity threshold, processing the bearer between theSeNB and the user terminal.

Optionally, the first check request message in step 110 in thisembodiment of the present disclosure further includes an identifier ofthe SeNB.

That the MeNB generates a second check request message according to thefirst identifier information, and sends the second check request messageto a user terminal, where the second check request message includesfirst indication information, and the first indication information isused to enable the user terminal to obtain second identifier informationthat matches the first identifier information, and a second data packetcount value corresponding to the second identifier information in step120 in this embodiment of the present disclosure includes that the MeNBgenerates the second check request message according to the firstidentifier information and the identifier of the SeNB, and sends thesecond check request message to the UE, such that the UE obtains,according to the second check request message, the second identifierinformation that matches the first identifier information and theidentifier of the SeNB, and the second data packet count valuecorresponding to the second identifier information.

Further, when the first check request message includes the identifier ofthe SeNB, the second identifier information is allocated by the SeNB.

Further, when the first check request message does not include theidentifier of the SeNB, the second identifier information is allocatedby the MeNB.

In this embodiment of the present disclosure, when the first checkrequest message includes the identifier of the SeNB, the identifier ofthe SeNB is further carried in a subsequent check response message, suchthat a receiver determines, according to the identifier, that the secondidentifier information is allocated by the SeNB.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack, and an MeNB receivesa first data packet count value that is of a bearer between the SeNB andUE and is sent by the SeNB, and requires, according to the first datapacket count value sent by the SeNB, the UE to report a second datapacket count value of a bearer between the UE and the SeNB. When thefirst data packet count value is the same as the second data packetcount value, the MeNB determines that no man-in-the-middle attack existsbetween the SeNB and the user terminal, and notifies the SeNB. Accordingto the technical solution of the present disclosure, in a scenario inwhich the SeNB offloads traffic of the MeNB, the MeNB, the SeNB, and theUE all can participate in detection of a man-in-the-middle attack.

Embodiment 2

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 2 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 2 of thepresent disclosure. FIG. 2 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 2 of the presentdisclosure, and this embodiment of the present disclosure is executed byan SeNB. As shown in FIG. 2, this embodiment includes the followingsteps.

Step 210: The SeNB sends a first check request message to an MeNB, wherethe first check request message includes first identifier information ofan ERAB and a first data packet count value corresponding to the firstidentifier information, and the first check request message is used toenable the MeNB to generate a second check request message according tothe first identifier information, and send the second check requestmessage to a user terminal.

In some implementations, the SeNB starts detection of a bearer betweenthe SeNB and the UE, and the SeNB sends the first check request messageto the MeNB, where the first check request message includes the firstidentifier information of the ERAB between the SeNB and the UE and thefirst data packet count value corresponding to the first identifierinformation.

The MeNB receives the first check request message, generates the secondcheck request message according to the first identifier information, andsends the second check request message to the UE.

A process in which the MeNB determines, according to the first datapacket count value and a second data packet count value reported by theUE, whether a man-in-the-middle attack exists between the SeNB and theUE is described in detail in the foregoing Embodiment 1, and is notrepeated here any further.

The second data packet count value is a data packet count valuecorresponding to second identifier information that matches the firstidentifier information.

Step 220: The SeNB receives the check response message sent by the MeNB.

Step 230: When the check response message is a second check responsemessage and the second check response message includes second indicationinformation, the SeNB determines, according to the second indicationinformation, that no man-in-the-middle attack exists between the SeNBand the user terminal.

In some implementations, if the MeNB determines that noman-in-the-middle attack exists between the SeNB and the UE, the checkresponse message determined by the MeNB is the second check responsemessage, the second check response message includes the secondindication information, and the SeNB determines, according to the secondindication information, that no man-in-the-middle attack exists betweenthe SeNB and the UE.

An implementation process of the second check response message isdescribed in detail in the foregoing Embodiment 1, and is not repeatedhere any further.

Step 240: When the check response message is a third check responsemessage and the third check response message includes third indicationinformation, the SeNB determines, according to the third indicationinformation, that a man-in-the-middle attack exists between the SeNB andthe user terminal, and takes a preset measure for processing.

In some implementations, if the MeNB determines that a man-in-the-middleattack exists between the SeNB and the UE, the check response messagedetermined by the MeNB is the third check response message, the thirdcheck response message includes the third indication information, andthe SeNB determines, according to the third indication information, thata man-in-the-middle attack exists between the SeNB and the UE.

An implementation process of the third check response message isdescribed in detail in the foregoing Embodiment 1, and is not repeatedhere any further.

Optionally, the first check request message sent by the SeNB to the MeNBin step 210 in this embodiment of the present disclosure furtherincludes an identifier of the SeNB.

That the SeNB sends a first check request message to an MeNB, where thefirst check request message includes first identifier information of anERAB and a first data packet count value corresponding to the firstidentifier information, and the first check request message is used toenable the MeNB to generate a second check request message according tothe first identifier information, and send the second check requestmessage to a user terminal in step 210 in this embodiment of the presentdisclosure includes that the SeNB sends the first check request messageto the MeNB, where the first check request message includes theidentifier of the SeNB, the first identifier information of the ERAB,and the first data packet count value corresponding to the firstidentifier information, and the first check request message is used toenable the MeNB to generate the second check request message accordingto the first identifier information and the identifier of the SeNB, andsend the second check request message to the user terminal.

Further, when the first check request message includes the identifier ofthe SeNB, the second identifier information is allocated by the SeNB.

Further, when the first check request message does not include theidentifier of the SeNB, the second identifier information is allocatedby the MeNB.

In this embodiment of the present disclosure, when the first checkrequest message includes the identifier of the SeNB, the identifier ofthe SeNB is further carried in a subsequent check response message, suchthat a receiver determines, according to the identifier, that the secondidentifier information is allocated by the SeNB.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack, and the SeNB receivesa check response message sent by an MeNB, and determines, according tothe check response message, whether a man-in-the-middle attack existsbetween the SeNB and UE. According to the technical solution of thepresent disclosure, in a scenario in which the SeNB offloads traffic ofthe MeNB, the MeNB, the SeNB, and the UE all can participate indetection of a man-in-the-middle attack.

Embodiment 3

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 3 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 3 of thepresent disclosure. FIG. 3 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 3 of the presentdisclosure, and this embodiment of the present disclosure is executed bya user terminal UE. As shown in FIG. 3, this embodiment includes thefollowing steps.

Step 310: The user terminal receives a second check request message sentby the MeNB, where the second check request message includes secondidentifier information corresponding to first identifier information ofan ERAB, and the second identifier information is a DRB(DRB)corresponding to the ERAB.

In some implementations, the SeNB starts detection of a bearer betweenthe SeNB and the UE, the SeNB sends a first check request message to theMeNB, and the MeNB receives the first check request message, andgenerates the second check request message according to the first checkrequest message, where the second check request message includes thefirst identifier information.

A detailed process in which the MeNB generates the second check requestmessage and a meaning of the first identifier information are describedin detail in the foregoing Embodiment 1, and are not repeated here anyfurther.

The first identifier information is an identifier of the ERAB betweenthe SeNB and the UE.

Step 320: The user terminal obtains the second identifier informationcorresponding to the first identifier information, and a second datapacket count value corresponding to the second identifier information.

In some implementations, the UE obtains the second data packet countvalue corresponding to the second identifier information.

The second data packet count value reflects a count, obtained by the UE,of sent and received data packets of the bearer between the SeNB and theUE.

Step 330: The user terminal sends the second identifier information andthe second data packet count value corresponding to the secondidentifier information to the MeNB, such that the MeNB determines,according to a first data packet count value and the second data packetcount value, whether a man-in-the-middle attack exists.

In some implementations, the UE sends the obtained second identifierinformation and the obtained second data packet count valuecorresponding to the second identifier information to the MeNB, suchthat the MeNB determines, according to the first data packet count valueand the second data packet count value, whether a man-in-the-middleattack exists.

Further, the first data packet count value reflects a count, obtained bythe SeNB, of sent and received data packets of the bearer between theSeNB and the UE, and the first data packet count value is correspondingto the first identifier information.

A described process in which the MeNB determines, according to the firstdata packet count value and the second data packet count value, whethera man-in-the-middle attack exists is described in detail in theforegoing Embodiment 1, and is not repeated here any further.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack, and a UE obtainssecond identifier information and a second data packet count valueaccording to first identifier information, and sends the second datapacket count value to an MeNB, such that the MeNB determines, accordingto a first data packet count value and the second data packet countvalue, whether a man-in-the-middle attack exists between the SeNB andthe UE, and notifies the SeNB. Therefore, a problem in other approachesthat a scenario in which the SeNB offloads traffic of the MeNB islimited to some extent is resolved, and a case in which the MeNB, theSeNB, and the UE all participate in detection of a man-in-the-middleattack is implemented.

Further, FIG. 4 is a signaling diagram of detection of aman-in-the-middle attack according to Embodiment 1, Embodiment 2, andEmbodiment 3 of the present disclosure, and the signaling diagram shownin FIG. 4 shows in detail a procedure of interaction among UE, an MeNB,and an SeNB. In FIG. 4, the MeNB identifies a first data packet countvalue and a second data packet count value, thereby implementing amethod for detecting a man-in-the-middle attack. The method fordetecting a man-in-the-middle attack in FIG. 4 may be executed accordingto a process described in the foregoing embodiment, and is not repeatedhere any further.

Embodiment 4

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 5 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 4 of thepresent disclosure. FIG. 5 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 4 of the presentdisclosure, and this embodiment of the present disclosure is executed byan MeNB. As shown in FIG. 5, this embodiment includes the followingsteps.

Step 510: The MeNB receives a first check request message sent by anSeNB, where the first check request message includes first identifierinformation of an ERAB and a first data packet count value correspondingto the first identifier information.

In some implementations, the SeNB starts detection of a bearer betweenthe SeNB and a UE, and the SeNB sends the first check request message tothe MeNB, where the first check request message includes the firstidentifier information of the ERAB between the SeNB and the UE and thefirst data packet count value corresponding to the first identifierinformation.

The first data packet count value reflects a count, obtained by theSeNB, of sent and received data packets of the bearer between the SeNBand the UE.

It may be understood that there are multiple bearers between the SeNBand the UE, and each bearer has one piece of first identifierinformation. In this embodiment of the present disclosure, the firstcheck request message includes at least two pieces of first identifierinformation corresponding to a bearer, and at least two first datapacket count values corresponding to the first identifier information.

The MeNB receives the first check request message.

Step 520: The MeNB generates a second check request message according tothe first identifier information and the first data packet count valuecorresponding to the first identifier information, and sends the secondcheck request message to a user terminal, where the second check requestmessage includes first indication information, the first indicationinformation is used to instruct the user terminal to obtain secondidentifier information that matches the first identifier information,and a second data packet count value corresponding to the secondidentifier information, and determine by comparison whether the firstdata packet count value is the same as the second data packet countvalue, and the second identifier information is a DRB corresponding tothe ERAB.

After receiving the first check request message, the MeNB determinesthat the SeNB starts detection of the bearer between the SeNB and theUE, and the MeNB obtains the first identifier information and the firstdata packet count value from the first check request message.

The MeNB generates the second check request message according to thefirst identifier information and the first data packet count value, andsends the second check request message to the UE, where the second checkrequest message includes the first indication information, and the firstindication information is used to instruct the UE to obtain the secondidentifier information that matches the first identifier information,and the second data packet count value corresponding to the secondidentifier information, and determine by comparison whether the firstdata packet count value is the same as the second data packet countvalue.

Further, in this embodiment of the present disclosure, the UE mayobtain, according to the first indication information, the secondidentifier information that matches the first identifier information andis of the DRB between the UE and the SeNB, and the second data packetcount value corresponding to the second identifier information.

The second data packet count value reflects a count, obtained by the UE,of sent and received data packets of the bearer between the SeNB and theUE.

It should be noted that because the first check request message mayinclude at least two pieces of first identifier information of a bearerand at least two corresponding first data packet count values in step510, when the UE obtains the second identifier information and thesecond data packet count value, the UE obtains, according to each pieceof first identifier information, second identifier informationcorresponding to each piece of first identifier information, and asecond data packet count value corresponding to the second identifier.

Step 530: The MeNB receives a check response message generated by theuser terminal according to the second check request message, and sendsthe check response message to the SeNB, such that the SeNB performsprocessing according to the check response message.

In some implementations, the UE determines by comparison whether thefirst data packet count value is the same as the second data packetcount value, and generates the check response message according to aresult of the comparing, and the UE sends the check response message tothe MeNB.

According to the foregoing descriptions in step 510 and step 520,because there are at least two pieces of first identifier information,at least two pieces of second identifier information, at least two firstdata packet count values, and at least two second data packet countvalues, and each piece of first identifier information is correspondingto each piece of second identifier information, that the UE determinesby comparison whether the first data packet count value is the same asthe second data packet count value is such that the UE determines bycomparison whether a first data packet count value corresponding to eachpiece of first identifier information is the same as a second datapacket count value corresponding to the second identifier informationthat matches each piece of first identifier information.

When first data packet count values corresponding to all firstidentifier information are the same as the second data packet countvalue corresponding to the second identifier information that matchesthe first identifier information, the UE determines that noman-in-the-middle attack exists between the SeNB and the UE.

When first data packet count values corresponding to at least two piecesof first identifier information are different from the second datapacket count value corresponding to the second identifier informationthat matches the first identifier information, the UE determines that aman-in-the-middle attack exists between the SeNB and the UE.

The MeNB receives the check response message sent by the UE according toa result of the comparing and a result of the determining, and sends thecheck response message to the SeNB, such that the SeNB performsprocessing according to the response message.

In an embodiment of the present disclosure, the UE identifies whetherthe first data packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information, and if the firstdata packet count value is the same as the second data packet countvalue, the UE determines that no man-in-the-middle attack exists betweenthe SeNB and the UE, and generates a first check response message. TheMeNB receives the first check response message sent by the UE, and sendsthe first check response message to the SeNB, such that the SeNBperforms processing according to the first check response message, wherethe first check response message includes a first indicationinformation, and the first indication information may be empty or may bea character string, such as a character string identifier “no” or “noman-in-the-middle attack exists”.

In another embodiment of the present disclosure, the UE identifieswhether the first data packet count value corresponding to the firstidentifier information is the same as the second data packet count valuecorresponding to the second identifier information, and if the firstdata packet count value is different from the second data packet countvalue, the UE determines that a man-in-the-middle attack exists betweenthe SeNB and the UE, and generates a second check response message. TheMeNB receives the second check response message sent by the UE, andsends the second check response message to the SeNB, such that the SeNBperforms processing according to the second check response message. Thesecond check response message includes second indication information,and the second indication information may further include all seconddata packet count values that are different from the first data packetcount value corresponding to the first identifier information, and firstidentifier information corresponding to the second data packet countvalues, such that the SeNB determines that a man-in-the-middle attackexists between the SeNB and the user terminal; or the third checkresponse message may include only a result of the determining, forexample, include a result that a man-in-the-middle attack exists or noman-in-the-middle attack exists.

In this embodiment of the present disclosure, the SeNB determines,according to the check response message, whether a man-in-the-middleattack exists between the SeNB and the UE. When the SeNB determines,according to the check response message, that a man-in-the-middle attackexists between the SeNB and the UE, the SeNB sends an exception reportto the MeNB.

Optionally, the first check request message sent in step 510 in thisembodiment of the present disclosure further includes an identifier ofthe SeNB.

That the MeNB generates a second check request message according to thefirst identifier information and the first data packet count valuecorresponding to the first identifier information, and sends the secondcheck request message to a user terminal, where the second check requestmessage includes first indication information, and the first indicationinformation is used to instruct the user terminal to obtain secondidentifier information that matches the first identifier information,and a second data packet count value corresponding to the secondidentifier information, and determine by comparison whether the firstdata packet count value is the same as the second data packet countvalue in step 520 in this embodiment of the present disclosure includesthat the MeNB generates the second check request message according tothe identifier of the SeNB, the first identifier information, and thefirst data packet count value corresponding to the first identifierinformation, and sends the second check request message to the UE, wherethe second check request message includes the first indicationinformation, and the first indication information is used to instructthe UE to obtain the second identifier information that matches thefirst identifier information, and the second data packet count valuecorresponding to the second identifier information, and determine bycomparison whether the first data packet count value is the same as thesecond data packet count value.

Further, when the first check request message includes the identifier ofthe SeNB, the second identifier information is allocated by the SeNB.

Further, when the first check request message does not include theidentifier of the SeNB, the second identifier information is allocatedby the MeNB.

In this embodiment of the present disclosure, when the first checkrequest message includes the identifier of the SeNB, the identifier ofthe SeNB is further carried in a subsequent check response message, suchthat a receiver determines, according to the identifier, that the secondidentifier information is allocated by the SeNB.

Optionally, after step 530 in this embodiment of the present disclosure,the method further includes a step in which the MeNB sends the exceptionreport to an MME or an O&M.

In some implementations, when the MeNB receives the exception reportsent by the SeNB, the MeNB sends the exception report to the MME or theO&M server.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack, and an MeNB sends asecond check request message to UE according to a first check requestmessage sent by the SeNB. When the UE determines, according to thesecond check request message, that a man-in-the-middle attack existsbetween the SeNB and the UE, the MeNB receives a check response messagesent by the UE, and forwards the check response message to the SeNB.According to the technical solution provided in the present disclosure,in a scenario in which the SeNB offloads traffic of the MeNB, the MeNB,the SeNB, and the UE all can participate in detection of aman-in-the-middle attack.

Embodiment 5

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 6 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 5 of thepresent disclosure. FIG. 6 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 5 of the presentdisclosure, and this embodiment of the present disclosure is executed byan SeNB. As shown in FIG. 6, this embodiment includes the followingsteps.

Step 610: The SeNB sends a first check request message to an MeNB, wherethe first check request message includes first indication information,and the first indication information is used to instruct the MeNB tosend a second check request message to a user terminal such as a UE.

In some implementations, the SeNB starts detection of a bearer betweenthe SeNB and the UE, and the SeNB sends the first check request messageto the MeNB, where the first check request message includes the firstindication information, and the first indication information is used toinstruct the MeNB to send the second check request message to the UE.

Content carried by the first check request message and a detailedprocess in which the MeNB sends the second check request message to theUE according to the first indication information are described in detailin the foregoing Embodiment 4, and are not repeated here any further.

Step 620: The SeNB receives a check response message sent by the MeNB.

In some implementations, the MeNB sends the second check request messageto the UE, such that the UE determines, according to the second checkrequest message, whether a man-in-the-middle attack exists between theSeNB and the UE, and sends the check response message to the MeNBaccording to a result of the determining. The MeNB sends the checkresponse message to the SeNB.

Step 630: The SeNB determines, according to the check response message,whether a man-in-the-middle attack exists.

In some implementations, the SeNB receives the check response message,and determines, according to the check response message, whether aman-in-the-middle attack exists.

Further, when the check response message carries a data packet countvalue fed back by the UE, the SeNB determines that a man-in-the-middleattack exists between the SeNB and the UE.

Step 640: When determining that the man-in-the-middle attack exists, theSeNB takes a preset measure for processing and sends an exception reportto the MeNB.

In some implementations, when the SeNB determines that aman-in-the-middle attack exists, the SeNB takes the preset measure forprocessing and sends the exception report to the MeNB, such that theMeNB sends the exception report to an MME or an O&M server.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack. When a UE determinesthat a man-in-the-middle attack exists between the SeNB and the UE, theSeNB receives a check response message sent by an MeNB, and determineswhether a man-in-the-middle attack exists between the SeNB and the UE.According to the technical solution provided in the present disclosure,in a scenario in which the SeNB offloads traffic of the MeNB, the MeNB,the SeNB, and the UE all can participate in detection of aman-in-the-middle attack.

Embodiment 6

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 7 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 6 of thepresent disclosure. FIG. 7 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 6 of the presentdisclosure, and this embodiment of the present disclosure is executed bya user terminal UE. As shown in FIG. 7, this embodiment includes thefollowing steps.

Step 710: The UE receives a second check request message sent by anMeNB, where the second check request message includes second identifierinformation corresponding to first identifier information of an ERAB,and a first data packet count value corresponding to the firstidentifier information, and the second identifier information is a DRBcorresponding to the ERAB.

In some implementations, the UE receives the second check requestmessage sent by the MeNB, where the second check request messageincludes the first identifier information of the ERAB between an SeNBand the UE and the first data packet count value corresponding to thefirst identifier information.

The first data packet count value reflects a count, obtained by theSeNB, of sent and received data packets of the bearer between the SeNBand the UE.

A detailed process in which the MeNB generates the second check requestmessage according to a first check request message sent by the SeNB andsends the second check request message to the UE, and content carried inthe first check request message are described in detail in the foregoingEmbodiment 4, and are not repeated here any further.

Step 720: The UE obtains the second identifier information correspondingto the first identifier information, and a second data packet countvalue corresponding to the second identifier information.

In some implementations, the UE obtains, according to the firstidentifier information included in the second check request message, thesecond identifier information corresponding to the first identifierinformation, and the second data packet count value corresponding to thesecond identifier information.

Further, in this embodiment of the present disclosure, the UE obtainsthe second identifier information and the second data packet count valuecorresponding to the second identifier information.

The second data packet count value reflects a count, obtained by the UE,of sent and received data packets of the bearer between the SeNB and theUE.

It should be noted that because the first check request message mayinclude at least two pieces of first identifier information of a bearerand at least two corresponding first data packet count values in step710, when the UE obtains the second identifier information and thesecond data packet count value, the UE obtains, according to each pieceof first identifier information, second identifier informationcorresponding to each piece of first identifier information, and asecond data packet count value corresponding to the second identifier.

Step 730: The UE determines, according to the first data packet countvalue corresponding to the first identifier information, and the seconddata packet count value corresponding to the second identifierinformation, whether a man-in-the-middle attack exists between an SeNBand the UE.

In some implementations, the UE determines by comparison whether thefirst data packet count value is the same as the second data packetcount value, and when the first data packet count value corresponding tothe first identifier information is the same as the second data packetcount value corresponding to the second identifier information, the UEdetermines that no man-in-the-middle attack exists between the SeNB andthe UE.

When the first data packet count value corresponding to the firstidentifier information is different from the second data packet countvalue corresponding to the second identifier information, the UEdetermines that a man-in-the-middle attack exists between the SeNB andthe UE.

Further, according to the foregoing description in step 720, becausethere are at least two pieces of first identifier information, at leasttwo pieces of second identifier information, at least two first datapacket count values, and at least two second data packet count values,and each piece of first identifier information is corresponding to eachpiece of second identifier information, that the UE determines bycomparison whether the first data packet count value is the same as thesecond data packet count value is such that the UE determines bycomparison whether a first data packet count value corresponding to eachpiece of first identifier information is the same as a second datapacket count value corresponding to the second identifier informationthat matches each piece of first identifier information.

When first data packet count values corresponding to all firstidentifier information are the same as the second data packet countvalue corresponding to the second identifier information that matchesthe first identifier information, the UE determines that noman-in-the-middle attack exists between the SeNB and the UE.

When first data packet count values corresponding to at least two piecesof first identifier information are different from the second datapacket count value corresponding to the second identifier informationthat matches the first identifier information, the UE determines that aman-in-the-middle attack exists between the SeNB and the UE.

Step 740: The UE generates a check response message according to aresult of the determining, and sends the check response message to theMeNB.

In some implementations, the UE generates the check response messageaccording to the result of the determining in step 730, and sends thecheck response message to the MeNB.

Further, in an implementation manner, the UE identifies whether thefirst data packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information, and if the firstdata packet count value is the same as the second data packet countvalue, the UE determines that no man-in-the-middle attack exists betweenthe SeNB and the UE, and generates a first check response message. TheMeNB receives the first check response message sent by the UE, and sendsthe first check response message to the SeNB, such that the SeNBperforms processing according to the first check response message.

In another implementation manner, the UE identifies whether the firstdata packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information. If the first datapacket count value is different from the second data packet count value,the UE determines that a man-in-the-middle attack exists between theSeNB and the UE, and generates a second check response message. The MeNBreceives the second check response message sent by the UE, and sends thesecond check response message to the SeNB, such that the SeNB performsprocessing according to the second check response message.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack, and a UE determines,according to a second check request message sent by an MeNB, whether aman-in-the-middle attack exists between the SeNB and the UE. When the UEdetermines that a man-in-the-middle attack exists between the SeNB andthe UE, the UE sends a check response message to the MeNB. According tothe technical solution provided in the present disclosure, in a scenarioin which the SeNB offloads traffic of the MeNB, the MeNB, the SeNB, andthe UE all can participate in detection of a man-in-the-middle attack.

Further, FIG. 8 is a signaling diagram of detection of aman-in-the-middle attack according to Embodiment 4, Embodiment 5, andEmbodiment 6 of the present disclosure, and the signaling diagram shownin FIG. 8 shows in detail a procedure of interaction among UE, an MeNB,and an SeNB. In FIG. 8, the UE compares a first data packet count valuewith a second data packet count value, thereby implementing a method fordetecting a man-in-the-middle attack. The method for detecting aman-in-the-middle attack in FIG. 8 may be executed according to aprocess described in the foregoing embodiment, and is not repeated hereany further.

Embodiment 7

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 9 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 7 of thepresent disclosure. FIG. 9 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 7 of the presentdisclosure, and this embodiment of the present disclosure is executed byan MeNB. As shown in FIG. 9, this embodiment includes the followingsteps.

Step 910: The MeNB receives a first check request message sent by anSeNB.

In some implementations, the SeNB starts detection of a bearer betweenthe SeNB and a UE, and the SeNB sends the first check request message tothe MeNB, where the first check request message is used to enable theMeNB to send a second check request message to the UE.

Step 920: The MeNB generates a second check request message according tothe first check request message and sends the second check requestmessage to the UE, where the second check request message includes firstindication information, and the first indication information is used toinstruct the UE to obtain first identifier information of a DRB and afirst data packet count value corresponding to the first identifierinformation.

In some implementations, after receiving the first check requestmessage, the MeNB determines that the SeNB starts detection of thebearer between the SeNB and the UE, and the MeNB determines, accordingto the first check request message, that the SeNB expects to receive adata packet count value that is of the bearer between the SeNB and theUE and is reported by the UE, and the MeNB generates the second checkrequest message and sends the second check request message to the UE.

Further, the second check request message includes the first indicationinformation, and in this embodiment of the present disclosure, the UEmay obtain, according to the first indication information, the firstidentifier information of the DRB between the UE and the SeNB and thefirst data packet count value corresponding to the first identifierinformation.

The first data packet count value reflects a count, obtained by the UE,of sent and received data packets of the bearer between the SeNB and theUE.

It may be understood that there are multiple bearers between the SeNBand the UE, and each bearer has a specified service. In this embodimentof the present disclosure, the SeNB may send one first check requestmessage to the MeNB, such that the UE reports at least two first datapacket count values corresponding to all bearers between the UE and theSeNB.

Step 930: The MeNB receives a check response message generated by the UEaccording to the second check request message, and sends the checkresponse message to the SeNB, where the response message includes thefirst identifier information and the first data packet count valuecorresponding to the first identifier information, such that the SeNBdetermines, according to the first data packet count value, whether aman-in-the-middle attack exists.

In some implementations, the UE obtains the first identifier informationand the first data packet count value according to the second checkrequest message. The UE adds the obtained first identifier informationand the obtained first data packet count value to the check responsemessage, and sends the check response message to the MeNB.

The MeNB receives a first check response message sent by the UE.

The check response message includes the first identifier information andthe first data packet count value corresponding to the first identifierinformation, such that the SeNB determines, according to the first datapacket count value, whether a man-in-the-middle attack exists.

Optionally, the first check request message received by the MeNB in step910 in this embodiment of the present disclosure further includes anidentifier of the SeNB.

That the MeNB generates a second check request message according to thefirst check request message, and sends the second check request messageto a user terminal, where the second check request message includesfirst indication information, and the first indication information isused to instruct the user terminal to obtain first identifierinformation of a DRB and a first data packet count value correspondingto the first identifier information in step 920 in this embodiment ofthe present disclosure includes that the MeNB generates the second checkrequest message according to the identifier of the SeNB and the firstcheck request message, and sends the second check request message to theUE. The second check request message includes the first indicationinformation, and the first indication information is used to instructthe UE to obtain the first identifier information and the first datapacket count value corresponding to the first identifier information.

Further, when the first check request message includes the identifier ofthe SeNB, the first identifier information is allocated by the SeNB.

Further, when the first check request message does not include theidentifier of the SeNB, the first identifier information is allocated bythe MeNB.

In this embodiment of the present disclosure, when the first checkrequest message includes the identifier of the SeNB, the identifier ofthe SeNB is further carried in a subsequent check response message, suchthat a receiver determines, according to the identifier, that the firstidentifier information is allocated by the SeNB.

Optionally, after step 930 in this embodiment of the present disclosure,the method further includes a step in which the MeNB sends an exceptionreport to an MME or an O&M server.

In some implementations, when the MeNB receives the exception reportsent by the SeNB, the MeNB sends the exception report to the MME or theO&M server.

The exception report sent by the SeNB is generated after the SeNBdetermines, according to the first data packet count value and a seconddata packet count value that is stored and obtained by the SeNB, whethera man-in-the-middle attack exists.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack. An MeNB sends asecond check request message to a UE according to a first check requestmessage sent by the SeNB, and forwards, to the SeNB, a check responsemessage fed back by the UE, such that the SeNB determines whether aman-in-the-middle attack exists between the SeNB and the UE, andnotifies the MeNB. According to the technical solution provided in thepresent disclosure, in a scenario in which the SeNB offloads traffic ofthe MeNB, the MeNB, the SeNB, and the UE all can participate indetection of a man-in-the-middle attack.

Embodiment 8

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 10 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 7 of thepresent disclosure. FIG. 10 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 7 of the presentdisclosure, and this embodiment of the present disclosure is executed byan SeNB. As shown in FIG. 10, this embodiment includes the followingsteps.

Step 1010: The SeNB sends a first check request message to an MeNB,where the first check request message is used to enable the MeNB togenerate a second check request message according to the first checkrequest message, and send the second check request message to a userterminal such as a UE.

In some implementations, the SeNB starts detection of a bearer betweenthe SeNB and UE, and the SeNB sends the first check request message tothe MeNB, where the first check request message is used to enable theMeNB to generate the second check request message and send the secondcheck request message to the UE.

A detailed process in which the MeNB generates the second check requestmessage and sends the second check request message to the UE isdescribed in detail in the foregoing Embodiment 8, and is not repeatedhere any further.

Step 1020: The SeNB receives a check response message sent by the MeNB,where the check response message includes first identifier informationof a DRB and a first data packet count value corresponding to the firstidentifier information.

In some implementations, the UE obtains, according to the second checkrequest message, the first identifier information of the DRB between theUE and the SeNB and the first data packet count value corresponding tothe first identifier information. The UE adds the first identifierinformation and the first data packet count value to the check responsemessage, and sends the check response message to the MeNB.

The MeNB sends the check response message to the SeNB.

The first data packet count value reflects a count, obtained by theSeNB, of sent and received data packets of the bearer between the SeNBand the UE.

It may be understood that there are multiple bearers between the SeNBand the UE, and each bearer has one piece of first identifierinformation. In this embodiment of the present disclosure, the firstcheck request message may include at least two pieces of firstidentifier information corresponding to a bearer, and at least two firstdata packet count values.

Step 1030: The SeNB obtains, according to the first identifierinformation, second identifier information that matches the firstidentifier information, and a second data packet count valuecorresponding to the second identifier information, where the secondidentifier information is an ERAB corresponding to the DRB.

In some implementations, after receiving the check response message, theSeNB obtains the first identifier information and the first data packetcount value from the check response message. The SeNB obtains, accordingto the first identifier information, the second identifier informationthat is corresponding to the first identifier information and is of theERAB between the SeNB and the UE and the second data packet count valuecorresponding to the second identifier information.

The second data packet count value reflects a count, obtained by theSeNB, of sent and received data packets of the bearer between the SeNBand the UE.

It should be noted that because the check response message includes atleast two pieces of first identifier information in step 1020, when theSeNB obtains the second identifier information that matches the firstidentifier information, and the second data packet count value, the SeNBobtains, according to each piece of first identifier information, secondidentifier information that matches each piece of first identifierinformation, and a second data packet count value corresponding to thesecond identifier information.

Step 1040: The SeNB determines, according to the first data packet countvalue and the second data packet count value, whether aman-in-the-middle attack exists.

In some implementations, the SeNB identifies whether the first datapacket count value is the same as the second data packet count value,and if the first data packet count value is the same as the second datapacket count value, the SeNB determines that no man-in-the-middle attackexists between the SeNB and the UE. Alternatively, if the first datapacket count value is different from the second data packet count value,the SeNB determines that a man-in-the-middle attack exists between theSeNB and the UE.

According to the foregoing descriptions in step 1020 and step 1030,because there are at least two pieces of first identifier information,at least two pieces of second identifier information, at least two firstdata packet count values, and at least two second data packet countvalues, and each piece of first identifier information is correspondingto each piece of second identifier information, that the SeNB determineswhether the first data packet count value is the same as the second datapacket count value is such that the SeNB identifies whether a first datapacket count value corresponding to each piece of second identifierinformation is the same as a second data packet count valuecorresponding to the first identifier information that matches eachpiece of second identifier information.

When the first data packet count value corresponding to the firstidentifier information is the same as the second data packet count valuecorresponding to the second identifier information, the SeNB determinesthat no man-in-the-middle attack exists between the SeNB and the UE.

That is, when first data packet count values corresponding to all firstidentifier information are the same as the second data packet countvalue corresponding to the second identifier information that matchesthe first identifier information, the SeNB determines that noman-in-the-middle attack exists between the SeNB and the UE.

When the first data packet count value corresponding to the firstidentifier information is different from the second data packet countvalue corresponding to the second identifier information, the SeNBdetermines that a man-in-the-middle attack exists between the SeNB andthe UE.

That is, when a first data packet count value corresponding to at leastone piece of first identifier information is different from the seconddata packet count value corresponding to the second identifierinformation that matches the first identifier information, the SeNBdetermines that a man-in-the-middle attack exists between the SeNB andthe UE.

Step 1050: When it is determined that the man-in-the-middle attackexists, the SeNB takes a preset measure for processing and send anexception report to the MeNB.

In some implementations, after the SeNB determines that aman-in-the-middle attack exists between the SeNB and the UE, the SeNBtakes the preset measure for processing and sends the exception reportto the MeNB, such that the MeNB sends the exception report to an MME oran O&M server, and the MME or the O&M server takes a further measure. Asan example instead of a limitation, the further measure is releasing ordeleting the bearer between the SeNB and the user terminal.Alternatively, the further measure is counting, by the MME or the O&Mserver, received exception reports, and when a quantity of exceptionreports exceeds a quantity threshold, processing the bearer between theSeNB and the UE.

Optionally, the first check request message in step 1010 in thisembodiment of the present disclosure further includes an identifier ofthe SeNB, and the second check request message further includes theidentifier of the SeNB.

Further, when the first check request message includes the identifier ofthe SeNB, the first identifier information is allocated by the SeNB.

Further, when the first check request message does not include theidentifier of the SeNB, the first identifier information is allocated bythe MeNB.

In this embodiment of the present disclosure, when the first checkrequest message includes the identifier of the SeNB, the identifier ofthe SeNB is further carried in a subsequent check response message, suchthat a receiver determines, according to the identifier, that the secondidentifier information is allocated by the SeNB.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack, and requires a UE toreport a first data packet count value of a bearer between the UE andthe SeNB. The SeNB determines, according to the first data packet countvalue and an obtained second data packet count value stored by the SeNB,whether a man-in-the-middle attack exists between the SeNB and the UE,and notifies an MeNB. According to the technical solution provided inthe present disclosure, in a scenario in which the SeNB offloads trafficof the MeNB, the MeNB, the SeNB, and the UE all can participate indetection of a man-in-the-middle attack.

Embodiment 9

For better understanding of the embodiments of the present disclosure,the following uses embodiments to provide further explanations withreference to the accompanying drawings, and the embodiments constituteno limitation to the embodiments of the present disclosure.

The following uses FIG. 11 as an example to describe in detail a methodfor detecting a man-in-the-middle attack provided in Embodiment 7 of thepresent disclosure. FIG. 11 is a flowchart of a method for detecting aman-in-the-middle attack according to Embodiment 7 of the presentdisclosure, and this embodiment of the present disclosure is executed bya user terminal UE. As shown in FIG. 11, this embodiment includes thefollowing steps.

Step 1110: The user terminal such as a UE receives a second checkrequest message sent by an MeNB.

In some implementations, an SeNB starts detection of a bearer betweenthe SeNB and the UE, and the SeNB sends a first check request message tothe MeNB, where the first check request message is used to enable theMeNB to generate the second check request message and send the secondcheck request message to the UE.

The UE receives the second check request message sent by the MeNB.

A detailed process in which the MeNB generates the second check requestmessage and sends the second check request message to the UE isdescribed in detail in the foregoing Embodiment 8, and is not repeatedhere any further.

Step 1120: The UE obtains, according to the second check requestmessage, first identifier information of a DRB and a first data packetcount value corresponding to the first identifier information.

In some implementations, the UE obtains, according to the second checkrequest message, the first identifier information of the DRB between theUE and the SeNB and the first data packet count value corresponding tothe first identifier information.

The first data packet count value reflects a count, obtained by theSeNB, of sent and received data packets of the bearer between the SeNBand the UE.

It may be understood that there are multiple bearers between the SeNBand the UE, and each bearer has one piece of first identifierinformation. In this embodiment of the present disclosure, the firstcheck request message may include at least two pieces of firstidentifier information corresponding to a bearer, and at least twocorresponding first data packet count values.

Step 1130: The UE sends a check response message to the MeNB, where thecheck response message includes the first identifier information and thefirst data packet count value corresponding to the first identifierinformation, such that the MeNB sends the check response message to anSeNB, and the SeNB determines, according to the first data packet countvalue, whether a man-in-the-middle attack exists between the SeNB andthe UE.

In some implementations, the UE adds the obtained first identifierinformation and the obtained first data packet count value to the checkresponse message, and sends the check response message to the MeNB.

The check response message includes the first identifier information andthe first data packet count value corresponding to the first identifierinformation, such that the MeNB sends the check response message to theSeNB, and the SeNB determines, according to the first data packet countvalue, whether a man-in-the-middle attack exists between the SeNB andthe UE.

Optionally, the first check request message received by the MeNB in step1110 in this embodiment of the present disclosure further includes anidentifier of the SeNB.

Further, when the first check request message includes the identifier ofthe SeNB, the first identifier information is allocated by the SeNB.

Further, when the first check request message does not include theidentifier of the SeNB, the first identifier information is allocated bythe MeNB.

In this embodiment of the present disclosure, when the first checkrequest message includes the identifier of the SeNB, the identifier ofthe SeNB is further carried in a subsequent check response message, suchthat a receiver determines, according to the identifier, that the firstidentifier information is allocated by the SeNB.

In conclusion, according to the method for detecting a man-in-the-middleattack provided in this embodiment of the present disclosure, an SeNBinitiates detection of a man-in-the-middle attack. A UE receives asecond check request message sent by an MeNB, and sends a check responsemessage to the MeNB according to the second check request message. TheMeNB forwards the check response message to the SeNB, such that the SeNBdetermines whether a man-in-the-middle attack exists between the SeNBand the UE. Therefore, a problem in other approaches that a scenario inwhich the SeNB offloads traffic of the MeNB is limited to some extent isresolved, and a case in which the MeNB, the SeNB, and the UE allparticipate in detection of a man-in-the-middle attack is implemented.

Further, FIG. 12 is a signaling diagram of detection of aman-in-the-middle attack according to Embodiment 7, Embodiment 8, andEmbodiment 9 of the present disclosure, and the signaling diagram shownin FIG. 12 shows in detail a procedure of interaction among UE, an MeNB,and an SeNB. In FIG. 12, the SeNB compares a first data packet countvalue with a second data packet count value, thereby implementing amethod for detecting a man-in-the-middle attack. The method fordetecting a man-in-the-middle attack in FIG. 12 may be executedaccording to a process described in the foregoing embodiment, and is notrepeated here any further.

Embodiment 10

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 13, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 1 of the present disclosure. Theapparatus includes a receiving unit 1310, a sending unit 1320, and ajudging unit 1330.

The receiving unit 1310 included in the apparatus is configured toreceive a first check request message sent by an SeNB, where the firstcheck request message includes first identifier information of an ERABand a first data packet count value corresponding to the firstidentifier information.

The sending unit 1320 is configured generate a second check requestmessage according to the first identifier information, and send thesecond check request message to a user terminal. The second checkrequest message includes first indication information used to instructthe user terminal to obtain second identifier information that matchesthe first identifier information, and a second data packet count valuecorresponding to the second identifier information, and the secondidentifier information is a DRB corresponding to the ERAB.

The receiving unit 1310 is further configured to receive a first checkresponse message generated by the user terminal according to the secondcheck request message, where the first check response message includesthe second identifier information and the second data packet countvalue.

The judging unit 1330 is configured such that when the first data packetcount value corresponding to the first identifier information is thesame as the second data packet count value corresponding to the secondidentifier information, the judging unit 1330 determines that noman-in-the-middle attack exists between the SeNB and the user terminal.Alternatively, when the first data packet count value corresponding tothe first identifier information is different from the second datapacket count value corresponding to the second identifier information,the judging unit 1330 determines that a man-in-the-middle attack existsbetween the SeNB and the user terminal.

The first check request message received by the receiving unit 1310further includes an identifier of the SeNB.

The sending unit 1320 is further configured to generate the second checkrequest message according to the first identifier information and theidentifier of the SeNB, and send the second check request message to theuser terminal, such that the user terminal obtains, according to thesecond check request message, the second identifier information thatmatches the first identifier information and the identifier of the SeNB,and the second data packet count value corresponding to the secondidentifier information.

The first check request message received by the receiving unit 1310includes at least two pieces of first identifier information and atleast two corresponding first data packet count values, and the firstcheck response message received by the receiving unit includes at leasttwo pieces of second identifier information and at least twocorresponding second data packet count values.

The judging unit 1330 is configured such that when a first data packetcount value corresponding to at least one piece of first identifierinformation is different from the second data packet count valuecorresponding to the second identifier information that matches thefirst identifier information, the judging unit 1330 determines that aman-in-the-middle attack exists between the SeNB and the UE.

The judging unit 1330 is configured such that when the first data packetcount values corresponding to all the first identifier information arethe same as the second data packet count value corresponding to thesecond identifier information that matches the first identifierinformation, the judging unit 1330 determines that no man-in-the-middleattack exists between the SeNB and the UE.

The sending unit 1320 is further configured to send a second checkresponse message to the SeNB, where the second check response messageincludes second indication information, and the second indicationinformation is used to indicate that no man-in-the-middle attack existsbetween the SeNB and the UE.

The sending unit 1320 is further configured to send an exception reportto an MME or an O&M server.

The sending unit 1320 is further configured to send a third checkresponse message to the SeNB, where the third check response messageincludes third indication information, and the third indicationinformation is used to indicate that a man-in-the-middle attack existsbetween the SeNB and the UE.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack.An MeNB receives a first data packet count value that is of a bearerbetween the SeNB and a UE and is sent by the SeNB, and requires,according to the first data packet count value sent by the SeNB, the UEto report a second data packet count value of a bearer between the UEand the SeNB. When the first data packet count value is different fromthe second data packet count value, the MeNB determines that noman-in-the-middle attack exists between the SeNB and the UE, andnotifies the SeNB. According to the technical solution and the apparatusin the present disclosure, in a scenario in which the SeNB offloadstraffic of the MeNB, the MeNB, the SeNB, and the UE all can participatein detection of a man-in-the-middle attack.

Embodiment 11

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 14, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 2 of the present disclosure. Theapparatus includes a sending unit 1410, a receiving unit 1420, and adetermining unit 1430.

The sending unit 1410 included in the apparatus is configured to send afirst check request message to an MeNB, where the first check requestmessage includes first identifier information of an ERAB and a firstdata packet count value corresponding to the first identifierinformation. The first check request message is used to enable the MeNBto generate a second check request message according to the firstidentifier information. Additionally, the sending unit 1410 isconfigured to send the second check request message to a user terminalsuch as a UE.

The receiving unit 1420 is configured to receive the check responsemessage sent by the MeNB.

The determining unit 1430 is configured such that when the checkresponse message is a second check response message and the second checkresponse message includes second indication information, the determiningunit 1430 determines, according to the second indication information,that no man-in-the-middle attack exists between the SeNB and the UE.Alternatively, when the check response message is a third check responsemessage and the third check response message includes third indicationinformation, the determining unit 1430 determines, according to thethird indication information, that a man-in-the-middle attack existsbetween the SeNB and the UE, and takes a preset measure for processing.

The first check request message sent by the sending unit 1410 furtherincludes an identifier of the SeNB.

The sending unit 1410 is configured to send the first check requestmessage to the MeNB, where the first check request message includes theidentifier of the apparatus, the first identifier information of theERAB, and the first data packet count value corresponding to the firstidentifier information. The first check request message is used toenable the MeNB to generate the second check request message accordingto the first identifier information and the identifier of the apparatus.The sending unit 1410 is further configured to send the second checkrequest message to the UE.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack.The SeNB receives a check response message sent by an MeNB, anddetermines, according to the check response message, whether aman-in-the-middle attack exists between the SeNB and a UE. According tothe technical solution of the present disclosure, in a scenario in whichthe SeNB offloads traffic of the MeNB, the MeNB, the SeNB, and the UEall can participate in detection of a man-in-the-middle attack.

Embodiment 12

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 15, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 3 of the present disclosure. Theapparatus includes a receiving unit 1510, an obtaining unit 1520, and asending unit 1530.

The receiving unit 1510 included in the apparatus is configured toreceive a second check request message sent by the MeNB, where thesecond check request message includes second identifier informationcorresponding to first identifier information of an ERAB, and the secondidentifier information is a DRB corresponding to the ERAB.

The obtaining unit 1520 is configured to obtain the second identifierinformation corresponding to the first identifier information, and asecond data packet count value corresponding to the second identifierinformation.

The sending unit 1530 is configured to send the second identifierinformation and the second data packet count value corresponding to thesecond identifier information to the MeNB, such that the MeNBdetermines, according to a first data packet count value and the seconddata packet count value, whether a man-in-the-middle attack exists.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack. AUE obtains second identifier information and a second data packet countvalue according to first identifier information, and sends the seconddata packet count value to an MeNB, such that the MeNB determines,according to a first data packet count value and the second data packetcount value, whether a man-in-the-middle attack exists between the SeNBand the UE, and notifies the SeNB. According to the technical solutionof the present disclosure, in a scenario in which the SeNB offloadstraffic of the MeNB, the MeNB, the SeNB, and the UE all can participatein detection of a man-in-the-middle attack.

Embodiment 13

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 16, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 4 of the present disclosure. Theapparatus includes a receiving unit 1610 and a sending unit 1620.

The receiving unit 1610 included in the apparatus is configured toreceive a first check request message sent by an SeNB, where the firstcheck request message includes first identifier information of an ERABand a first data packet count value corresponding to the firstidentifier information.

The sending unit 1620 is configured to generate a second check requestmessage according to the first identifier information and the first datapacket count value corresponding to the first identifier information,and send the second check request message to a user terminal (e.g., UE),where the second check request message includes first indicationinformation, the first indication information is used to instruct theuser terminal to obtain second identifier information that matches thefirst identifier information, and a second data packet count valuecorresponding to the second identifier information, and determine bycomparison whether the first data packet count value corresponding tothe first identifier information is the same as the second data packetcount value corresponding to the second identifier information, and thesecond identifier information is a DRB corresponding to the ERAB.

The receiving unit 1610 is further configured to receive a checkresponse message generated by the user terminal according to the secondcheck request message, and send the check response message to the SeNB,such that the SeNB performs processing according to the responsemessage.

The first check request message received by the receiving unit 1610further includes an identifier of the SeNB.

The sending unit 1620 is configured to generate the second check requestmessage according to the identifier of the SeNB, the first identifierinformation, and the first data packet count value corresponding to thefirst identifier information, and send the second check request messageto the user terminal, where the second check request message includesthe first indication information, and the first indication informationis used to instruct the user terminal to obtain the second identifierinformation that matches the first identifier information and theidentifier of the SeNB, and the second data packet count valuecorresponding to the second identifier information, and determine bycomparison whether the first data packet count value corresponding tothe first identifier information is the same as the second data packetcount value corresponding to the second identifier information.

The sending unit 1620 is further configured such that when the receivingunit receives an exception report sent by the SeNB, the sending unit1620 sends the exception report to an MME or an O&M server.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack,and an MeNB sends a second check request message to a UE according to afirst check request message sent by the SeNB. When the UE determines,according to the second check request message, that a man-in-the-middleattack exists between the SeNB and the UE, the MeNB receives a checkresponse message sent by the UE, and forwards the check response messageto the SeNB. According to the technical solution of the presentdisclosure, in a scenario in which the SeNB offloads traffic of theMeNB, the MeNB, the SeNB, and the UE all can participate in detection ofa man-in-the-middle attack.

Embodiment 14

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 17, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 5 of the present disclosure. Theapparatus includes a sending unit 1710, a receiving unit 1720, and adetermining unit 1730.

The sending unit 1710 included in the apparatus is configured to send afirst check request message to an MeNB, where the first check requestmessage includes first indication information, and the first indicationinformation is used to instruct the MeNB to send a second check requestmessage to a user terminal.

The receiving unit 1720 is configured to receive a check responsemessage sent by the MeNB.

The determining unit 1730 is configured to determine, according to thecheck response message, whether a man-in-the-middle attack exists.

The sending unit 1710 is further configured such that when thedetermining unit 1730 determines that the man-in-the-middle attackexists, the sending unit 1710 takes a preset measure for processing andsend an exception report to the MeNB.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack.When a UE determines that a man-in-the-middle attack exists between theSeNB and the UE, the SeNB receives a check response message sent by anMeNB, and determines whether a man-in-the-middle attack exists betweenthe SeNB and the UE. According to the technical solution of the presentdisclosure, in a scenario in which the SeNB offloads traffic of theMeNB, the MeNB, the SeNB, and the UE all can participate in detection ofa man-in-the-middle attack.

Embodiment 15

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 18, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 6 of the present disclosure. Theapparatus includes a receiving unit 1810, an obtaining unit 1820, ajudging unit 1830, and a sending unit 1840.

The receiving unit 1810 included in the apparatus is configured toreceive a second check request message sent by an MeNB, where the secondcheck request message includes second identifier informationcorresponding to first identifier information of an ERAB, and a firstdata packet count value corresponding to the first identifierinformation, and the second identifier information is a DRBcorresponding to the ERAB.

The obtaining unit 1820 is configured to obtain the second identifierinformation corresponding to the first identifier information, and asecond data packet count value corresponding to the second identifierinformation.

The judging unit 1830 is configured to determine, according to the firstdata packet count value corresponding to the first identifierinformation, and the second data packet count value corresponding to thesecond identifier information, whether a man-in-the-middle attack existsbetween an SeNB and the apparatus.

The sending unit 1840 is configured to generate a check response messageaccording to a result determined by the judging unit, and send the checkresponse message to the MeNB.

The judging unit 1830 is configured such that when the first data packetcount value corresponding to the first identifier information is thesame as the second data packet count value corresponding to the secondidentifier information, the judging unit 1830 determines that noman-in-the-middle attack exists between the SeNB and the apparatus.Alternatively, when the first data packet count value corresponding tothe first identifier information is different from the second datapacket count value corresponding to the second identifier information,the judging unit 1830 determines that a man-in-the-middle attack existsbetween the SeNB and the apparatus.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack,and a UE determines, according to a second check request message sent byan MeNB, whether a man-in-the-middle attack exists between the SeNB andthe UE. When the UE determines that a man-in-the-middle attack existsbetween the SeNB and the UE, the UE sends a check response message tothe MeNB. According to the technical solution of the present disclosure,in a scenario in which the SeNB offloads traffic of the MeNB, the MeNB,the SeNB, and the UE all can participate in detection of aman-in-the-middle attack.

Embodiment 16

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 19, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 7 of the present disclosure. Theapparatus includes a receiving unit 1910 and a sending unit 1920.

The receiving unit 1910 included in the apparatus is configured toreceive a first check request message sent by an SeNB.

The sending unit 1920 is configured to generate a second check requestmessage according to the first check request message, and send thesecond check request message to a user terminal, where the second checkrequest message includes first indication information, and the firstindication information is used to instruct the user terminal to obtainfirst identifier information of a DRB and a first data packet countvalue corresponding to the first identifier information.

The receiving unit 1910 is further configured to receive a checkresponse message generated by the user terminal according to the secondcheck request message, and send the check response message to the SeNB,where the response message includes the first identifier information andthe first data packet count value corresponding to the first identifierinformation, such that the SeNB determines, according to the first datapacket count value, whether a man-in-the-middle attack exists.

The first check request message received by the receiving unit 1910further includes an identifier of the SeNB.

The sending unit 1920 is configured to generate the second check requestmessage according to the identifier of the SeNB and the first checkrequest message, and send the second check request message to the userterminal, where the second check request message includes the firstindication information, and the first indication information is used toinstruct the user terminal to obtain the first identifier information ofthe DRB and the first data packet count value corresponding to the firstidentifier information.

The sending unit 1920 is further configured such that when the receivingunit receives an exception report sent by the SeNB, the sending unit1920 sends the exception report to an MME or an O&M server.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack.An MeNB sends a second check request message to a UE according to afirst check request message sent by the SeNB, and forwards, to the SeNB,a check response message fed back by the UE, such that the SeNBdetermines whether a man-in-the-middle attack exists between the SeNBand the UE, and notifies the MeNB. According to the technical solutionof the present disclosure, in a scenario in which the SeNB offloadstraffic of the MeNB, the MeNB, the SeNB, and the UE all can participatein detection of a man-in-the-middle attack.

Embodiment 17

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 20, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 8 of the present disclosure. Theapparatus includes a sending unit 2010, a receiving unit 2020, anobtaining unit 2030, and a judging unit 2040.

The sending unit 2010 included in the apparatus is configured to send afirst check request message to an MeNB, where the first check requestmessage is used to enable the MeNB to generate a second check requestmessage according to the first check request message, and send thesecond check request message to a user terminal.

The receiving unit 2020 is configured to receive a check responsemessage sent by the MeNB, where the check response message includesfirst identifier information of a DRB and a first data packet countvalue corresponding to the first identifier information.

The obtaining unit 2030 is configured to obtain, according to the firstidentifier information, second identifier information that matches thefirst identifier information, and a second data packet count valuecorresponding to the second identifier information, where the secondidentifier information is an ERAB corresponding to the DRB.

The judging unit 2040 is configured to determine, according to the firstdata packet count value and the second data packet count value, whethera man-in-the-middle attack exists.

The sending unit 2010 is further configured such that when the judgingunit 2040 determines that the man-in-the-middle attack exists, thesending unit 2010 take a preset measure for processing and send anexception report to the MeNB.

The judging unit 2040 is configured such that when the first data packetcount value corresponding to the first identifier information is thesame as the second data packet count value corresponding to the secondidentifier information, the judging unit 2040 determines that noman-in-the-middle attack exists between the apparatus and the userterminal. Alternatively, when the first data packet count valuecorresponding to the first identifier information is different from thesecond data packet count value corresponding to the second identifierinformation, the judging unit 2040 determines that a man-in-the-middleattack exists between the apparatus and the user terminal.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack,and requires a UE to report a first data packet count value of a bearerbetween the UE and the SeNB. The SeNB determines, according to the firstdata packet count value and an obtained second data packet count valuestored by the SeNB, whether a man-in-the-middle attack exists betweenthe SeNB and the UE, and notifies an MeNB. According to the technicalsolution of the present disclosure, in a scenario in which the SeNBoffloads traffic of the MeNB, the MeNB, the SeNB, and the UE all canparticipate in detection of a man-in-the-middle attack.

Embodiment 18

Accordingly, an embodiment of the present disclosure further provides anapparatus for detecting a man-in-the-middle attack. An implementationstructure of the apparatus is shown in FIG. 21, and the apparatus isconfigured to implement the method for detecting a man-in-the-middleattack in the foregoing Embodiment 9 of the present disclosure. Theapparatus includes a receiving unit 2110, an obtaining unit 2120, and asending unit 2130.

The receiving unit 2110 included in the apparatus is configured toreceive a second check request message sent by an MeNB.

The obtaining unit 2120 is configured to obtain, according to the secondcheck request message, first identifier information of a DRB and a firstdata packet count value corresponding to the first identifierinformation.

The sending unit 2130 is configured to send a check response message tothe MeNB, where the check response message includes the first identifierinformation and the first data packet count value corresponding to thefirst identifier information, such that the MeNB sends the checkresponse message to an SeNB, and the SeNB determines, according to thefirst data packet count value, whether a man-in-the-middle attack existsbetween the SeNB and the apparatus.

In conclusion, according to the apparatus for detecting aman-in-the-middle attack provided in this embodiment of the presentdisclosure, an SeNB initiates detection of a man-in-the-middle attack. AUE receives a second check request message sent by an MeNB, and sends acheck response message to the MeNB according to the second check requestmessage. The MeNB forwards the check response message to the SeNB, suchthat the SeNB determines whether a man-in-the-middle attack existsbetween the SeNB and the UE. According to the technical solution of thepresent disclosure, in a scenario in which the SeNB offloads traffic ofthe MeNB, the MeNB, the SeNB, and the UE all can participate indetection of a man-in-the-middle attack.

Embodiment 19

In addition, the apparatus for detecting a man-in-the-middle attackprovided in Embodiment 10 of the present disclosure may also beimplemented in the following manner, in order to implement the foregoingmethod for detecting a man-in-the-middle attack in Embodiment 1 of thepresent disclosure. As shown in FIG. 22, the apparatus for detecting aman-in-the-middle attack includes a network interface 2210, a processor2220, a memory 2230 and a system bus 2240. The system bus 2240 isconfigured to connect the network interface 2210, the processor 2220,and the memory 2230.

The network interface 2210 is configured to perform interaction andcommunication with a UE and an SeNB.

The memory 2230 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2230 is configured to store anapplication program, where the application program may be used to enablethe processor 2220 to access and execute instructions. The instructionsinclude: receiving a first check request message sent by an SeNB, wherethe first check request message includes first identifier information ofan ERAB and a first data packet count value corresponding to the firstidentifier information; generating a second check request messageaccording to the first identifier information, and sending the secondcheck request message to a user terminal, where the second check requestmessage includes first indication information, the first indicationinformation is used to instruct the user terminal to obtain secondidentifier information that matches the first identifier information,and a second data packet count value corresponding to the secondidentifier information, and the second identifier information is a DRBcorresponding to the ERAB; receiving a first check response messagegenerated by the user terminal according to the second check requestmessage, where the first check response message includes the secondidentifier information and the second data packet count value; anddetermining, when the first data packet count value corresponding to thefirst identifier information is the same as the second data packet countvalue corresponding to the second identifier information, that noman-in-the-middle attack exists between the SeNB and the user terminal;or determining, when the first data packet count value corresponding tothe first identifier information is different from the second datapacket count value corresponding to the second identifier information,that a man-in-the-middle attack exists between the SeNB and the userterminal.

Further, the first check request message further includes an identifierof the SeNB.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute a process of generating a second check request message accordingto the first identifier information, and sending the second checkrequest message to a user terminal, where the second check requestmessage includes first indication information, the first indicationinformation is used to enable the user terminal to obtain secondidentifier information that matches the first identifier information,and a second data packet count value corresponding to the secondidentifier information, where executing the process comprises:generating the second check request message according to the firstidentifier information and the identifier of the SeNB, and sending thesecond check request message to the user terminal, such that the userterminal obtains, according to the second check request message, thesecond identifier information that matches the first identifierinformation and the identifier of the SeNB, and the second data packetcount value corresponding to the second identifier information.

Further, the first check request message includes at least two pieces offirst identifier information and at least two corresponding first datapacket count values, and the first check response message includes atleast two pieces of second identifier information and at least twocorresponding second data packet count values.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute a process of the determining, when the first data packet countvalue corresponding to the first identifier information is differentfrom the second data packet count value corresponding to the secondidentifier information, that a man-in-the-middle attack exists betweenthe SeNB and the user terminal, where executing the process comprises:determining, when a first data packet count value corresponding to atleast one piece of first identifier information is different from thesecond data packet count value corresponding to the second identifierinformation that matches the first identifier information, that aman-in-the-middle attack exists between the SeNB and the user terminal.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute a process of determining, when the first data packet count valuecorresponding to the first identifier information is the same as thesecond data packet count value corresponding to the second identifierinformation, that no man-in-the-middle attack exists between the SeNBand the user terminal, where executing the process comprises:determining, when the first data packet count values corresponding toall the first identifier information are the same as the second datapacket count value corresponding to the second identifier informationthat matches the first identifier information, that no man-in-the-middleattack exists between the SeNB and the user terminal.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute the following process of sending a second check response messageto the SeNB, where the second check response message includes secondindication information, and the second indication information is used toindicate that no man-in-the-middle attack exists between the SeNB andthe UE.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute the following process or sending an exception report to an MMEor an O&M server.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute the following process of sending a third check response messageto the SeNB, where the third check response message includes thirdindication information, and the third indication information is used toindicate that a man-in-the-middle attack exists between the SeNB and theuser terminal.

In addition, as shown in FIG. 22, the apparatus for detecting aman-in-the-middle attack provided in Embodiment 13 of the presentdisclosure may also be implemented in the following manner, in order toimplement the foregoing method for detecting a man-in-the-middle attackin Embodiment 4 of the present disclosure.

The memory 2230 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2230 is configured to store anapplication program, where the application program may be used to enablethe processor 2220 to access and execute the following instructions:receiving a first check request message sent by an SeNB, where the firstcheck request message includes first identifier information of an ERABand a first data packet count value corresponding to the firstidentifier information; generating a second check request messageaccording to the first identifier information and the first data packetcount value corresponding to the first identifier information, andsending the second check request message to a user terminal, where thesecond check request message includes first indication information, thefirst indication information is used to instruct the user terminal toobtain second identifier information that matches the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information, and determine by comparison whether thefirst data packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information, and the secondidentifier information is a DRB corresponding to the ERAB; and receivinga check response message generated by the user terminal according to thesecond check request message, and sending the check response message tothe SeNB, such that the SeNB performs processing according to theresponse message.

Further, the first check request message further includes an identifierof the SeNB.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute a process of generating a second check request message accordingto the first identifier information and the first data packet countvalue corresponding to the first identifier information, and sending thesecond check request message to a user terminal, where the second checkrequest message includes first indication information, and the firstindication information is used to instruct the user terminal to obtainsecond identifier information that matches the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information, and determine by comparison whether thefirst data packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information, where executing theprocess comprises: generating the second check request message accordingto the identifier of the SeNB, the first identifier information, and thefirst data packet count value corresponding to the first identifierinformation, and sending the second check request message to the userterminal, where the second check request message includes the firstindication information, and the first indication information is used toinstruct the user terminal to obtain the second identifier informationthat matches the first identifier information and the identifier of theSeNB, and the second data packet count value corresponding to the secondidentifier information, and determine by comparison whether the firstdata packet count value corresponding to the first identifierinformation is the same as the second data packet count valuecorresponding to the second identifier information.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute a process when the MeNB receives an exception report sent by theSeNB, where executing the process comprises sending the exception reportto an MME or an O&M server.

In addition, as shown in FIG. 22, the apparatus for detecting aman-in-the-middle attack provided in Embodiment 16 of the presentdisclosure may also be implemented in the following manner, in order toimplement the foregoing method for detecting a man-in-the-middle attackin Embodiment 7 of the present disclosure.

The memory 2230 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2230 is configured to store anapplication program, where the application program may be used to enablethe processor 2220 to access and execute the following instructions:receiving a first check request message sent by an SeNB; generating asecond check request message according to the first check requestmessage, and sending the second check request message to a userterminal, where the second check request message includes firstindication information, and the first indication information is used toinstruct the user terminal to obtain first identifier information of aDRB and a first data packet count value corresponding to the firstidentifier information; and receiving a check response message generatedby the user terminal according to the second check request message, andsending the check response message to the SeNB, where the responsemessage includes the first identifier information and the first datapacket count value corresponding to the first identifier information,such that the SeNB determines, according to the first data packet countvalue, whether a man-in-the-middle attack exists.

Further, the first check request message further includes an identifierof the SeNB.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute a process of generating a second check request message accordingto the first check request message, and sending the second check requestmessage to a user terminal, where the second check request messageincludes first indication information, and the first indicationinformation is used to instruct the user terminal to obtain firstidentifier information of a DRB and a first data packet count valuecorresponding to the first identifier information, where executing theprocess comprises: generating the second check request message accordingto the identifier of the SeNB and the first check request message, andsending the second check request message to the user terminal, where thesecond check request message includes the first indication information,and the first indication information is used to instruct the userterminal to obtain the first identifier information of the DRB and thefirst data packet count value corresponding to the first identifierinformation.

Further, the application program stored in the memory 2230 furtherincludes an instruction that may be used to enable the processor 2220 toexecute a process when the apparatus receives an exception report sentby the SeNB, where executing the process comprises sending the exceptionreport to an MME or an O&M server.

Embodiment 20

In addition, the apparatus for detecting a man-in-the-middle attackprovided in Embodiment 11 of the present disclosure may also beimplemented in the following manner, in order to implement the foregoingmethod for detecting a man-in-the-middle attack in Embodiment 2 of thepresent disclosure. As shown in FIG. 23, the apparatus for detecting aman-in-the-middle attack includes a network interface 2310, a processor2320, and a memory 2330. A system bus 2340 is configured to connect thenetwork interface 2310, the processor 2320, and the memory 2330.

The network interface 2310 is configured to perform interaction andcommunication with an MeNB and UE.

The memory 2330 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2330 is configured to store anapplication program, where the application program may be used to enablethe processor 2320 to access and execute the following instructions:sending a first check request message to an MeNB, where the first checkrequest message includes first identifier information of an ERAB and afirst data packet count value corresponding to the first identifierinformation, and the first check request message is used to enable theMeNB to generate a second check request message according to the firstidentifier information, and send the second check request message to auser terminal; receiving the check response message sent by the MeNB;and when the check response message is a second check response messageand the second check response message includes second indicationinformation, determining, according to the second indicationinformation, that no man-in-the-middle attack exists between the SeNBand the user terminal; or when the check response message is a thirdcheck response message and the third check response message includesthird indication information, determining, according to the thirdindication information, that a man-in-the-middle attack exists betweenthe SeNB and the user terminal, and taking a preset measure forprocessing.

Further, the first check request message further includes an identifierof the apparatus.

Further, the application program stored in the memory 2330 furtherincludes an instruction that may be used to enable the processor 2320 toexecute a process of sending a first check request message to an MeNB,where the first check request message includes first identifierinformation of an ERAB and a first data packet count value correspondingto the first identifier information, and the first check request messageis used to enable the MeNB to generate a second check request messageaccording to the first identifier information, and send the second checkrequest message to a user terminal, where executing the processcomprises: sending the first check request message to the MeNB, wherethe first check request message includes the identifier of theapparatus, the first identifier information of the ERAB, and the firstdata packet count value corresponding to the first identifierinformation, and the first check request message is used to enable theMeNB to generate the second check request message according to the firstidentifier information and the identifier of the SeNB, and send thesecond check request message to the user terminal.

In addition, as shown in FIG. 23, the apparatus for detecting aman-in-the-middle attack provided in Embodiment 14 of the presentdisclosure may also be implemented in the following manner, in order toimplement the foregoing method for detecting a man-in-the-middle attackin Embodiment 5 of the present disclosure.

The memory 2330 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2330 is configured to store anapplication program, where the application program may be used to enablethe processor 2320 to access and execute the following instructions:sending a first check request message to an MeNB, where the first checkrequest message includes first indication information, and the firstindication information is used to instruct the MeNB to send a secondcheck request message to a user terminal; receiving a check responsemessage sent by the MeNB; determining, according to the check responsemessage, whether a man-in-the-middle attack exists; and when it isdetermined that the man-in-the-middle attack exists, taking a presetmeasure for processing and sending an exception report to the MeNB.

In addition, as shown in FIG. 23, the apparatus for detecting aman-in-the-middle attack provided in Embodiment 17 of the presentdisclosure may also be implemented in the following manner, in order toimplement the foregoing method for detecting a man-in-the-middle attackin Embodiment 8 of the present disclosure.

The memory 2330 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2330 is configured to store anapplication program, where the application program may be used to enablethe processor 2320 to access and execute the following instructions:sending a first check request message to an MeNB, where the first checkrequest message is used to enable the MeNB to generate a second checkrequest message according to the first check request message, and sendthe second check request message to a user terminal; receiving a checkresponse message sent by the MeNB, where the check response messageincludes first identifier information of a DRB and a first data packetcount value corresponding to the first identifier information;obtaining, according to the first identifier information, secondidentifier information that matches the first identifier information,and a second data packet count value corresponding to the secondidentifier information, where the second identifier information is anERAB corresponding to the DRB; determining, according to the first datapacket count value and the second data packet count value, whether aman-in-the-middle attack exists; and when it is determined that theman-in-the-middle attack exists, taking a preset measure for processingand sending an exception report to the MeNB.

Further, the application program stored in the memory 2330 furtherincludes an instruction that may be used to enable the processor 2320 toexecute a process of determining, according to the first data packetcount value and the second data packet count value, whether aman-in-the-middle attack exists, where executing the process ofdetermining comprises: when the first data packet count valuecorresponding to the first identifier information is the same as thesecond data packet count value corresponding to the second identifierinformation, determining that no man-in-the-middle attack exists betweenthe apparatus and the user terminal. Alternatively, executing theprocess of determining comprises: when the first data packet count valuecorresponding to the first identifier information is different from thesecond data packet count value corresponding to the second identifierinformation, determining that a man-in-the-middle attack exists betweenthe apparatus and the user terminal.

Embodiment 21

In addition, the apparatus for detecting a man-in-the-middle attackprovided in Embodiment 12 of the present disclosure may also beimplemented in the following manner, in order to implement the foregoingmethod for detecting a man-in-the-middle attack in Embodiment 3 of thepresent disclosure. As shown in FIG. 24, the apparatus for detecting aman-in-the-middle attack includes a network interface 2410, a processor2420, a memory 2430 and a system bus 2440. The system bus 2440 isconfigured to connect the network interface 2410, the processor 2420,and the memory 2430.

The network interface 2410 is configured to perform interaction andcommunication with a UE and an MeNB.

The memory 2430 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2430 is configured to store anapplication program, where the application program may be used to enablethe processor 2420 to access and execute the following instructions:receiving a second check request message sent by the MeNB, where thesecond check request message includes second identifier informationcorresponding to first identifier information of an ERAB, and the secondidentifier information is a DRB corresponding to the ERAB; obtaining thesecond identifier information corresponding to the first identifierinformation, and a second data packet count value corresponding to thesecond identifier information; and sending the second identifierinformation and the second data packet count value corresponding to thesecond identifier information to the MeNB, such that the MeNBdetermines, according to a first data packet count value and the seconddata packet count value, whether a man-in-the-middle attack exists.

In addition, as shown in FIG. 23, the apparatus for detecting aman-in-the-middle attack provided in Embodiment 15 of the presentdisclosure may also be implemented in the following manner, in order toimplement the foregoing method for detecting a man-in-the-middle attackin Embodiment 6 of the present disclosure.

The memory 2330 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2330 is configured to store anapplication program, where the application program may be used to enablethe processor 2320 to access and execute the following instructions:receiving a second check request message sent by an MeNB, where thesecond check request message includes second identifier informationcorresponding to first identifier information of an ERAB, and a firstdata packet count value corresponding to the first identifierinformation, and the second identifier information is a DRBcorresponding to the ERAB; obtaining the second identifier informationcorresponding to the first identifier information, and a second datapacket count value corresponding to the second identifier information;determining, according to the first data packet count valuecorresponding to the first identifier information, and the second datapacket count value corresponding to the second identifier information,whether a man-in-the-middle attack exists between an SeNB and theapparatus; and generating a check response message according to a resultof the determining, and sending the check response message to the MeNB.

Further, the application program stored in the memory 2430 furtherincludes an instruction that may be used to enable the processor 2420 toexecute a process of determining, according to the first data packetcount value corresponding to the first identifier information, and thesecond data packet count value corresponding to the second identifierinformation, whether a man-in-the-middle attack exists between an SeNBand the apparatus, where executing the process of determining comprises:when the first data packet count value corresponding to the firstidentifier information is the same as the second data packet count valuecorresponding to the second identifier information, determining that noman-in-the-middle attack exists between the SeNB and the apparatus.Alternatively, executing the process of determining comprises: when thefirst data packet count value corresponding to the first identifierinformation is different from the second data packet count valuecorresponding to the second identifier information, determining that aman-in-the-middle attack exists between the SeNB and the apparatus.

In addition, as shown in FIG. 23, the apparatus for detecting aman-in-the-middle attack provided in Embodiment 18 of the presentdisclosure may also be implemented in the following manner, in order toimplement the foregoing method for detecting a man-in-the-middle attackin Embodiment 9 of the present disclosure.

The memory 2330 may be a permanent memory, for example, a hard diskdrive and a flash memory, and the memory 2330 is configured to store anapplication program, where the application program may be used to enablethe processor 2320 to access and execute the following instructions:receiving a second check request message sent by an MeNB; obtaining,according to the second check request message, first identifierinformation of a DRB and a first data packet count value correspondingto the first identifier information; and sending a check responsemessage to the MeNB, where the check response message includes the firstidentifier information and the first data packet count valuecorresponding to the first identifier information, such that the MeNBsends the check response message to an SeNB, and the SeNB determines,according to the first data packet count value, whether aman-in-the-middle attack exists between the SeNB and the apparatus.

Further embodiments of the present disclosure are provided in thefollowing. It should be noted that the numbering used in the followingsection does not necessarily need to comply with the numbering used inthe previous sections.

A person skilled in the art may be further aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware, computer software, or a combination thereof. Toclearly describe the interchangeability between the hardware and thesoftware, the foregoing has generally described compositions and stepsof each example according to functions. Whether the functions areperformed by hardware or software depends on particular applications anddesign constraint conditions of the technical solutions. A personskilled in the art may use different methods to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of the presentdisclosure.

Steps of methods or algorithms described in the embodiments disclosed inthis specification may be implemented by hardware, a software moduleexecuted by a processor, or a combination thereof. The software modulemay reside in a random access memory (RAM), a memory, a read-only memory(ROM), an electrically programmable ROM, an electrically erasableprogrammable ROM, a register, a hard disk, a removable disk, or anyother form of storage medium known in the art.

In the foregoing implementation manners, the objective, technicalsolutions, and benefits of the present disclosure are further describedin detail. It should be understood that the foregoing descriptions aremerely example implementation manners of the present disclosure, but arenot intended to limit the protection scope of the present disclosure.Any modification, equivalent replacement, or improvement made withoutdeparting from the principle of the present disclosure should fallwithin the protection scope of the present disclosure.

What is claimed is:
 1. A method for detecting a man-in-the-middleattack, the method comprising: sending, by a secondary base station, afirst check request message to a master base station, wherein the firstcheck request message comprises first identifier information of anevolved random access bearer (ERAB) and a first data packet count valuecorresponding to the first identifier information; receiving, by themaster base station, the first check request message; obtaining, by themaster base station, second identifier information that matches thefirst identifier information, wherein the second identifier informationis an identifier of a data radio bearer (DRB) corresponding to the ERAB;sending, by the master base station, a second check request message to auser terminal, wherein the second check request message comprises thefirst data packet count value and the second identifier information; andreceiving, by the master base station, a check response message from theuser terminal.
 2. The method according to claim 1, further comprising:receiving, by the user terminal, the second check request message;determining, by the user terminal, whether a second data packet countvalue is equal to the first data packet count value, wherein the seconddata packet count value corresponds to the second identifierinformation; and sending, by the user terminal, the check responsemessage to the master base station.
 3. The method according to claim 2,further comprising generating, by the user terminal, the check responsemessage based on determining whether the second data packet count valueis equal to the first data packet count value.
 4. The method accordingto claim 2, further comprising sending, by the master base station, anexception report to a mobility management entity or an operation andmaintenance server when the check response message comprises the seconddata packet count value.
 5. The method according to claim 2, wherein thefirst data packet count value reflects a count, obtained by thesecondary base station, of sent and received data packets of a bearerbetween the secondary base station and the user terminal.
 6. The methodaccording to claim 2, wherein the second data packet count valuereflects a count, obtained by the user terminal, of sent and receiveddata packets of a bearer between the secondary base station and the userterminal.
 7. A system for detecting a man-in-the-middle attack, whereinthe system comprises: a master base station; and a secondary basestation configured to send a first check request message, wherein thefirst check request message comprises first identifier information of anevolved random access bearer (ERAB) and a first data packet count valuecorresponding to the first identifier information, wherein the masterbase station is configured to: receive the first check request message;obtain second identifier information that matches the first identifierinformation, wherein the second identifier information is an identifierof a data radio bearer (DRB) corresponding to the ERAB; send a secondcheck request message to a user terminal, wherein the second checkrequest message comprises the first data packet count value and thesecond identifier information; and receive a check response message fromthe user terminal.
 8. The system according to claim 7, wherein the userterminal is configured to: receive the second check request message;determine whether a second data packet count value is equal to the firstdata packet count value, wherein the second data packet count valuecorresponds to the second identifier information; and send the checkresponse message to the master base station.
 9. The system according toclaim 8, wherein the user terminal is further configured to generate thecheck response message based on determining whether the second datapacket count value is equal to the first data packet count value. 10.The system according to claim 8, wherein the master base station isfurther configured to send an exception report to a mobility managemententity or an operation and maintenance server when the check responsemessage comprises the second data packet count value.
 11. The systemaccording to claim 8, wherein the first data packet count value reflectsa count, obtained by the secondary base station, of sent and receiveddata packets of a bearer between the secondary base station and the userterminal.
 12. The system according to claim 8, wherein the second datapacket count value reflects a count, obtained by the user terminal, ofsent and received data packets of a bearer between the secondary basestation and the user terminal.
 13. A method for detecting aman-in-the-middle attack, the method comprising: receiving, by a masterbase station, a first check request message from a secondary basestation, wherein the first check request message comprises firstidentifier information of an evolved random access bearer (ERAB) and afirst data packet count value corresponding to the first identifierinformation; obtaining, by the master base station, second identifierinformation that matches the first identifier information, wherein thesecond identifier information is an identifier of a data radio bearer(DRB) corresponding to the ERAB; sending, by the master base station, asecond check request message to a user terminal, wherein the secondcheck request message comprises the first data packet count value andthe second identifier information that matches the first identifierinformation; and receiving, by the master base station, a check responsemessage from the user terminal.
 14. The method according to claim 13wherein the check response message comprises a second data packet countvalue.
 15. The method according to claim 13, further comprising sending,by the master base station, an exception report to a mobility managemententity or an operation and maintenance server.
 16. The method accordingto claim 13, wherein the first data packet count value reflects a count,obtained by the secondary base station, of sent and received datapackets of a bearer between the secondary base station and the userterminal.
 17. The method according to claim 14, wherein the second datapacket count value reflects a count, obtained by the user terminal, ofsent and received data packets of a bearer between the secondary basestation and the user terminal.
 18. An apparatus comprising: a networkinterface; and a processor coupled to the network interface, wherein theprocessor is configured to: receive a first check request message from asecondary base station through the network interface, wherein the firstcheck request message comprises first identifier information of anevolved random access bearer (ERAB) and a first data packet count valuecorresponding to the first identifier information; obtain secondidentifier information that matches the first identifier information,wherein the second identifier information is an identifier of a dataradio bearer (DRB) corresponding to the ERAB; send a second checkrequest message to a user terminal through the network interface,wherein the second check request message comprises the first data packetcount value and the second identifier information that matches the firstidentifier information; and receive a check response message from theuser terminal through the network interface.
 19. The apparatus accordingto claim 18, wherein the check response message comprises a second datapacket count value.
 20. The apparatus according to claim 18, wherein theprocessor is further configured to send an exception report to amobility management entity or an operation and maintenance server.